The excessive use of antibiotics has triggered the appearance of new resistant strains, which is why great interest has been taken in the search for new bioactive compounds capable of overcoming this emergency in recent years. Massive sequencing tools have enabled the detection of new microorganisms that cannot be cultured in a laboratory, thus opening the door to the search for new biosynthetic genes. The great variety in oceanic environments in terms of pressure, salinity, temperature, and nutrients enables marine microorganisms to develop unique biochemical and physiological properties for their survival, enhancing the production of secondary metabolites that can vary from those produced by terrestrial microorganisms. We performed a search for type I PKS genes in metagenomes obtained from the marine sediments of the deep waters of the Gulf of Mexico using Hidden Markov Models. More than 2000 candidate genes were detected in the metagenomes that code for type I PKS domains, while biosynthetic pathways that may code for other secondary metabolites were also detected. Our research demonstrates the great potential use of the marine sediments of the Gulf of Mexico for identifying genes that code for new secondary metabolites. New antibiotics are urgently required to combat the emerging multi-drug resistant pathogens and new infectious agents . In theiSecondary metabolites are produced by biosynthetic gene clusters, which are organized groups of two or more genes that encode a biosynthetic pathway to produce specialized metabolites . NonriboCovering approximately 70% of the surface of the earth, the oceans are an invaluable source of new natural products . With maAmong the main problems encountered by the present study during the assembly of environmental samples were the low coverage and the formation of chimeras ,16,17. AWhile the initial size of the assemblies was greater than 500 Mbp, after filtering with a contig cutoff >500 bp, the size decreased significantly, probably due to their high levels of fragmentation and low contiguity in them. The longest contigs corresponded to sample C13 and those with a size > 40 Kbp. However, these curated metagenomes still harbored more than 475,202 coding sequences with potential as novel bioactive compound pathways or functional elements. Raw data and a full quality assessment corresponding to the metagenome assemblies are shown in Due to the drastic decrease in the contigs’ size, the coverage and diversity was evaluated based on the short reads, using the Nonpareil software ,22, withThe PKS I domains were identified by HMMer search using a predefined set of models . The seaProteobacteria and Firmicutes, while, in the kingdom of Archaea the phylum Euryarchaeota is the most common carrier of these domains. The FOCUS taxonomic profiling results for contigs containing PKS I domains are shown in The normalization of the data and correspondence analysis indicate that the KS, KR, MT, ER, ACP, and AT domains are related (clustering close each other), while the TE and DH domains presented a minor relative abundance in our data (the TE domain was not found in the B7 and C13 metagenomes) . The disThe synthesis of secondary metabolites by bacteria helps to defend against predators and enables cell communication, among other functions, making secondary metabolites an excellent source of bioactive compounds for use in human therapies . Deep-waThe most represented metabolic pathway was the biosynthesis of prodigiosin, an antimicrobial agent with little toxicity. Another pathway detected in the metagenomes obtained was the production of monoterpenoid, which consists of a ten-carbon backbone (two isoprene units) structure and can be divided into three subgroups: acyclic, monocyclic, and bicyclic . Some moAfter binning was performed, the metagenome-assembled genomes (MAGs) were analyzed using the antiSMASH software, bacterial version 6.0, to find biosynthetic clusters. While most of the clusters obtained were incomplete, due to the short length of the contigs obtained, we were able to detect domains involved in the synthesis of the bioactive compounds from our samples.Desulfobacteraceae family (genomic Mash distance 0.07). The BinC10_2 contained domains that may code for NRPS and terpene, while BinC10_5 presented both the highest abundance of biosynthetic genes, which code for the RiPP recognition element (RRE), and the synthesis of terpene, ladderane, and type III PKS.The assembly of the C10 metagenome presented the highest quality , in thatType I PKS produces a large family of medicinally important natural products. As PKS I multidomain proteins can be long and present a high degree of complexity, in most metagenomic sequences, the fragments of these proteins contain a simple domain . The lowhttp://enve-omics.ce.gatech.edu/nonpareil/faq (accessed on 25 May 2022): B7 = 23.17; C10 = 23.05; C13 = 23.03; C14 = 22.92; and D18 = 22.96). This finding also supports the conclusion that the genomic space captured in our data is representative of the type of biomes analyzed.An average coverage (close to 0.2) consistent with complex and highly diverse communities (such as those found in marine sediments) was observed in our data set. The statistics obtained by the present study coincide with metagenomic observations obtained by other studies in complex environmental samples, such as soil, tropical forest, or seawater. Said studies obtained coverage levels that were always < 40%, which coincides with the greater level of diversity found in their samples than in other biomes, such as animal host microbiomes or enriched communities whose coverage has been found to be >60% by similar sequencing efforts ,28. TherDegenerate primers are usually used to identify KS and ACP domains in biodiversity studies or for the identification of new biosynthetic clusters , which lProteobacteria, Firmicutes, Actinobacteria, Plantomycetes, and Cyanobacteria [Actinobacteria [Actinobacteria [Streptomyces continues to be the predominant source of new chemistries, with 167 new metabolites reported during 2018, representing >69% of the marine-sourced bacterial natural products [Roseovarius tolerans [Rhodovulum sulfidophilum [Aequorivita sp. [Streptomyces is due to the fact that they are culturable microorganisms and they are highly represented in annotation databases. The phylum found by the present study to present the highest number of PKS I domains is Proteobacteria, which is the most abundant phylum found in marine environments (with an abundance between 50% and 80%); however, very few bioactive compounds have been described in these microorganisms [Our results are consistent with the biodiversity studies carried out in the GoM, which have found that its sediments largely contain the phyla bacteria ,31, whicbacteria ,33,34. Hbacteria ,35, and bacteria ,37. The products , althougtolerans , Rhodovudophilum , and Aeqvita sp. . It cannrganisms .Actinomycetales, Clostridiales, Planctomycetales, Rhizobiales, and Spirochaetales are the orders that present more than two PKS domains in their sequences. While Clostridiales presents limited natural products, the genomic analysis conducted on these strict anaerobes shows the presence of natural product biosynthetic gene clusters that can code for entirely new products [Planctomycetales isolated from macroalgae obtained off the Portuguese coast, finding that 95% contained one or both of the bioactive genes PKS and NRPS; in addition, they also found antifungal and antibacterial activity in the bioactivity tests conducted on the samples [Rhizobiales includes species of the genera Agrobacterium, Blastobacter, Mesorhizobium, and Ochrobactrum, which have been associated with bioactive compounds of marine origin, in contrast with Spirochaetales, for which no marine bioactive metabolites have been reported in the Comprehensive Marine Natural Products Database [The taxonomic profiling carried out by our study found that products . Graça e samples . The ordDatabase .Serratia, Hahella, Streptomyces, Zooshikella, Vibrio, and Pseudomonas [Prodigiosin is one of the secondary metabolites that are encoded in the metagenomes analyzed in this study. This red tripyrrole pigment, belonging to the prodiginines family, is produced by several bacterial genera, such as udomonas , and is udomonas ,47. Geneudomonas . Moreoveudomonas . Of the udomonas .Actinomycetes strains and are molecules that have been proven to have very potent anticancer, antibacterial, and antiviral effects [S. aureus infection [Among the antibiotic biosynthesis pathways found in the metagenomes analyzed are ansamycins, enediyne, vancomycin, streptomycin, and validamycin. Ansamycins are a group of antibiotics produced by several  effects . Enediyn effects . Vancomynfection .Streptomyces [Rhizoctonia solani for over 50 years in China, with no validamycin-resistant isolates reported in the field [The first of the class of aminoglycoside antibiotics to be discovered was the first antibiotic remedy for tuberculosis  and was ptomyces . Streptoptomyces , which hhe field ,53.Desulfobateraceae family and represents a new species (MASH distance 0.07) with an unexplored genomic context.The search for biosynthetic clusters in the metagenome bins found the presence of RiPPs. Research conducted in the 20th century identified many classes of natural products, with four groups being particularly prevalent , while, more recently, RiPPs have also been described . RiPP bi2H4) and hydroxylamine (NH2OH), within the anammoxosome [Candidatus Scalindua genus (Mash distance 0.2), a genus described from natural habitats, especially from marine sediments and oxygen minimum zones [Candidatus is a taxonomic status for uncultured prokaryotic cells [Several biosynthetic clusters have also been detected in BinC10_5: RRE, terpene, ladderane, and type III PKS. While the terpene biosynthesis pathway is well known to be present in many plant and fungi genomes, it was recently proposed that it is also widely distributed in bacterial genomes . Largelymoxosome . The ideum zones ,63,64. CPrevious studies show that geographic location, latitude, and pH are determining factors in the diversity of biosynthetic genes and environmental microbiomes ,65,66. TThe sediments were collected onboard the R/V Justo Sierra (UNAM) during the MMF-01 oceanographic campaign from 25 February to 18 March 2016. Eighteen sampling sites were selected from the Perdido and Coatzacoalcos regions and equally distributed between the two. Sampling was undertaken at a seafloor depth ranging from 550 to 3400 m using a box core, with subsampling then directly obtained from the box core using sterile syringes inserted at a depth of up to 10 cm. Each subsample was frozen and stored immediately in liquid nitrogen onboard and kept at −80 °C when they arrived to the laboratory, until nucleic acid extraction could be performed. For this study the results of the 16S-rDNA sequencing (see ) corresp®, Hilden, Germany) following the protocol provided by manufacturer, with some modifications. During the lysis step, 275 µL of phenol-chloroform-isoamyl alcohol (25:24:1) solution was added, followed by 5 min incubation at room temperature to increase cell lysis. The elution step was performed twice using 50 µL of elution buffer with the column incubated for 10 min at room temperature. All centrifuge steps were performed at 14,000× g. Eluted DNA was quantified via UV absorption analysis  and the quality of the extracted DNA was verified on an agarose gel electrophoresis. DNA was stored at −20 °C until further analysis.DNA was extracted from three independent syringes from each sampling site using the DNeasy PowerSoil Kit (QiagenPaired-end metagenome sequencing was performed in a NovaSeq instrument (2 × 150 bp) at MR DNA .The quality of the short reads (151 pb) was assessed using the FastQC software version v0.11.5 and low-quality bases (Q < 30) and adapters were removed using AfterQC version 0.9.6, which was configured with the paired-end mode and default options . The reahttps://github.com/ayixon/RaPDTool (accessed on 25 May 2022). The relative abundance profiles using FOCUS were directly loaded in the web biodiversity calculator , to obtain the Shannon index, the Equitability index, and the Margalef Richness index. The metagenome coverage was estimated using the Nonpareil software version 3.401 [The five metagenomes reported in the present study were profiled from both the short reads (null model for diversity) and the curated assemblies using the FOCUS software  with a eon 3.401 ,22, appl--cut_tc option “trusted cutoff (TC)”) [−4 were selected and aligned using MAFFT v7.453 [The Hidden Markov Models for each of the PKS I domains (acyltransferase (AT), acyl carrier proteins (ACP), enoyl reductase (ER), ketoreductase (KR), ketosynthase (KS), methyltransferase (MT), dehydratase (DH), and thioesterase (TE)) were downloaded from the Pfam database, version 33.1 . The modf (TC)”) . SequencT v7.453 . The aliT v7.453 ,79. The T v7.453 .https://github.com/takaram/kofam_scan, accessed on 25 May 2022) [The Kofam_scan tool, version to 1.3.0 (ay 2022) , was appay 2022) . Draft eay 2022)  and thenay 2022) , in ordeay 2022) , while tay 2022) . The binay 2022) .


Histiocytic sarcoma is a rare malignant tumor that is similar in characteristics to a mature histiocyte/macrophage and is a relatively new disease entity. In approximately one-third of cases, the site of origin is a lymph node; development from the gastrointestinal tract, spleen, soft tissue, and skin has further been reported. The tumor characteristics are not well-understood as reports on its clinical presentation and treatment are limited. We report a case of duodenal primary histiocytic sarcoma.An elevated lesion in the second part of the duodenum was detected in a 70-year-old woman during routine examination using upper gastrointestinal tract endoscopy. Blood biochemistry findings were normal for tumor markers. No abnormal findings were observed in the blood count and biochemical examination. Upper gastrointestinal endoscopy revealed a 20-mm elevated lesion with a slight depression in the center, opposite to the papilla of the descending duodenum. The biopsy showed erosions of the mucosal epithelium and inflammatory cell infiltration, but no evidence of malignancy. Ultrasound-guided endoscopy revealed an ischemic tumor of submucosal origin, and bowel biopsy suggested a histiocytic sarcoma. Distant metastasis and lymph node enlargement were absent on abdominal sonography, computed tomography, and magnetic resonance imaging. Duodenal segmental resection was performed. Immunostaining of the excised lesion was positive for CD68, CD163, CD4, CD5, CD15, and CD45 and negative for CD1a, CD21, CD34, MPO, and S-100 protein. Ki-67 positivity was approximately 20%. Based on these findings, the diagnosis of histiocytic sarcoma was confirmed. Ten months after the surgery, a lymph node recurrence in the dorsum of the pancreatic uncus was observed. No evidence of recurrence was found in any other part; hence, we performed pancreaticoduodenectomy. Pathological findings of the excised lymph node confirmed the recurrence of histiocytic sarcoma in the lymph node.This is the first reported case of a duodenal primary histiocytic sarcoma with recurrence in the lymph node after the primary resection. The patient was treated for recurrence by lymph node excision and pancreaticoduodenectomy. Tumors arising from histiocytes have been defined using different terms in the past, such as histiocytic lymphoma, histiocytic medullary reticulosis, or monocytic sarcoma; however, the nomenclature remains evolving . AccordiThe patient was a 70-year-old woman with an insignificant medical and family history. She visited a primary care family doctor for a routine clinical examination and underwent an upper gastrointestinal tract endoscopy. An elevated lesion was detected in the second part of the duodenum, and the patient was referred to our hospital for further examination.On physical examination, no significant abnormalities were observed. Moreover, blood test findings were normal for tumor markers: the cancer antigen 19-9 and the carcinoembryonic antigen levels were 17.8 U/mL  and 2.1 ng/mL , respectively. No abnormal findings were observed in the blood count and biochemical examination.Endoscopy of the upper gastrointestinal tract Fig.  revealedBased on the ultrasound-guided endoscopic examination Fig. , we concThe bowel biopsy revealed tumor cells composed of proliferating atypical cells with a prominent nucleolus in a large nucleus and an acidophilic cytoplasm. Immunostaining was positive for CD68 and CD163 and negative for CD1a, CD21, HMB45, and S-100 protein. Abdominal sonography, computed tomography (CT), and magnetic resonance imaging (MRI) revealed no enlargement and distant metastasis to the lymph nodes. Positron emission tomography (PET) showed a mildly high maximum standardized uptake value (SUV-MAX) of 4.2 for the tumor site. Accumulation was absent in other sites apart from the tumor.A diagnosis of primary HS of duodenal origin was made based on these findings, and surgery was chosen as the primary treatment. The tumor diameter was relatively small, and it was predicted that the tumor had invaded the muscularis. Moreover, no malignancy was found during imaging; hence, lymph node dissection was considered unnecessary. The duodenal segmental resection was limited to the duodenal papilla, and the tumor was enucleated with a secure margin.The gross examination showed a yellowish white mass lesion, 16 × 8 mm in size, histologically extending from the lamina propria to the muscularis mucosa Fig. . AdditioThe patient’s postoperative course was insignificant, and she was discharged on day 15 after surgery.Ten months after the surgery, enlarged lymph nodes were detected in the dorsum of the pancreatic uncus on CT Fig. . The lymSignificant hyperplasia of blasts with an acidophilic cytoplasm, similar to that in the primary tumor, was noted during the pathological examination of the enlarged dorsal caput pancreatic lymph nodes; immunostaining was positive for CD68, CD163, CD4, CD5, CD15, and CD45 and negative for CD1a, CD21, CD34, MPO, and S-100 protein. Thus, we confirmed lymph node recurrence of the primary HS. Additionally, enlargement of the lymph nodes near the circumference of the SMA and the dorsal caput pancreatic lymph nodes were noted macroscopically; however, pathological examination revealed neoplastic tissue only in the dorsal caput pancreatic lymph nodes. There was no evidence of lymphatic or venous invasion. At the time of writing this case report, 11 months have passed since the recurrence; the patient is alive and has not experienced another recurrence.Histopathologically, HS develops from a diffuse proliferation of cells with an acidophilic cytoplasm or cells with abundant foamy cytoplasm; dyskaryosis is strong, and imaging studies often reveal apoptotic cells and nuclear fission. Moreover, HS is often associated with reactive inflammatory cell infiltration. Because the cells in an HS can have an irregular, round, and spindle-shaped morphology, it may be difficult to distinguish an HS from a diffuse large B-cell lymphoma . HoweverThe epidemiological characteristics of HS are unclear as there are only a few reported cases. The age of onset varies widely, ranging from 20 to 89 years. . There aIn a report on five cases of splenic primary HS, thrombocytopenia was observed in all cases . However14 In the present case, because the tumor was a small lesion limited to the duodenal descending limb during the time of the initial surgery, we chose duodenal segmental resection. However, the lesion recurred in the lymph nodes around the pancreatic uncus, 10 months after the surgery for the primary lesion. In this scenario, we could have initially chosen to perform a pancreatoduodenectomy, including a D2 dissection. However, because the prognosis of HS is poor, the prognosis was expected to remain the same even with a regional lymph node resection. Thus, the accumulation of evidence from future cases is crucial to establish the disease course and suitable therapy.Regarding gastrointestinal primary HS, we retrieved 15 cases reported from 2001 through 2021 using the keyword “histiocytic sarcoma” in PubMed and searching for “gastrointestinal tract”; thus, a total of 16 cases, including ours, were reviewed. To the best of our knowledge, this is the first reported case of an HS in the duodenum (Table In conclusion, a gastrointestinal primary HS recurrence has not been reported previously, and this is the first such case report.


The bidirectional analysis demonstrated that genetic predisposition to IBS was associated with a decreased level of PTH . In conclusion, the present study indicates no causal relationship between the serum calcium and Vit-D concentrations and the risk of IBS. The potential mechanisms via which IBS affects serum PTH need to be further investigated.Several observational studies have indicated the potential associations among calcium, vitamin D (Vit-D), and irritable bowel syndrome (IBS). However, the causal relationship deduced from these studies is subject to residual confounding factors and reverse causation. Therefore, we aimed to explore the bidirectional causal effects among serum calcium, Vit-D, PTH, and IBS at the genetic level by a two-sample Mendelian randomization (MR) analysis of the datasets from IEU OpenGWAS database. Sensitivity analyses were performed to evaluate the robustness. The estimates were presented as odds ratios (ORs) with their 95% confidence intervals (CIs). The results of the inverse variance weighted method did not reveal any causal relationship between the genetically predisposed calcium (OR = 0.92, 95% CI: 0.80–1.06,  Irritable bowel syndrome (IBS) is one of the most common gastrointestinal diseases, and affects approximately 5–10% of the global population, which exerts an immense impact on the patient’s quality of life, society, and economy . FurtherRecent studies demonstrate that the diet and micronutrients play a vital role in the pathophysiology of IBS, and over 80% of IBS patients report food triggers for their complaints, such as dairy products, gluten, alcohol, and fried foods ,7. NotewCalcium homeostasis, which plays a vital role in various cellular and biological processes, is mainly regulated by concerted action of the calciotropic hormones, such as Vit-D and parathyroid hormone (PTH) . StudiesBased on Mendel’s law of inheritance, Mendelian randomization (MR) analysis can use genetic variants, namely single-nucleotide polymorphisms (SNPs), as instrumental variables (IVs) to estimate the causal effects of the predefined exposure on outcome . Since gTo investigate the causality between exposures and disease, we conducted two-sample MR analysis that used genetic variants as instrumental variables to explore the causal effects of risk factors on outcomes. Compared with observational studies, MR can avoid reverse causation and reduce confounding factors. The graphical flow of the experimental design is shown in The validity of MR analysis relies on three assumptions: (1) there is strong association between the IVs and the exposure; (2) each IV is not associated with confounding variables; (3) each IV is only associated with the outcome through the exposure; there are no alternative pathways for the association.https://gwas.mrcieu.ac.uk/, accessed on 10 October 2022), a database of 244,879,032,980 genetic associations from 42,334 GWAS summary datasets, for query or download.The data of our study were obtained from the IEU OpenGWAS database  to select the SNPs genetically associated with the traits. To avoid inaccurate results due to too few SNPs, the significance threshold of PTH data was relaxed to 5 × 10−6. Secondly, we utilized the linkage disequilibrium clumping to exclude some undesirable SNPs (r2 > 0.001). Thirdly, we harmonized the respective exposure and outcome datasets using effect allele frequencies, while removing palindromic SNPs with intermediate allele frequencies. Lastly, according to the third assumption of MR that genetic variation cannot be associated with any possible confounding factor, we used PhenoScanner V2 [p < 1 × 10−5) with confounding factors such as drinking [Firstly, the summary-level data above for Vit-D and calcium were screened by the genome-wide significance /(1 − R2). R2 and N refer to the cumulative explained variance of selected SNPs and sample size separately [2 was calculated using the formula R2 = 2 × MAF × (1 − MAF) × Beta2 [The IV exposure strength of genetic instruments was assessed from the F statistic using an approximation. If F > 10, there is sufficient strength to avoid a problem of weak instrument bias in the two-sample model. The F statistics were computed by the admittedly reliable formula F = Rparately . R2 was  × Beta2 .Multiple approaches were used in our study. We utilized the method of inverse variance weighted (IVW) as the primary analysis for its efficiency to estimate the causal effect. The weighted median was used as auxiliary method when the heterogeneity was significant, and the MR-Egger regression method was used to assess the pleiotropy by intercept test. According to the assumption of MR analysis, the instrumental variable must be only associated with the outcome through the risk factor; thus, if there are other pathways via which the outcome is influenced by genetic variants, bias will occur, and the horizontal pleiotropy may increase the false positive rate. Therefore, the pleiotropy should be evaluated using the method of MR-Egger and MR-PRESSO. The former can evaluate the potential pleiotropy in the IVW model, and the latter is used for testing horizontal pleiotropy via identifying and removing outlying instrumental variables . The leave-one-out sensitivity analysis was performed to evaluate the robustness of the study findings. The estimates were presented as odds ratios (ORs) with their 95% confidence intervals (CIs) per one standard deviation (SD) increase in the exposures. The statistical analyses above were performed in R 4.1.3 with R package of “TwoSampleMR” (version 0.5.6) and “MRPRESSO”.p < 5 × 10−8). As for PTH, 15 SNPs were screened for instrumental variables (p < 5 × 10−6). After linkage disequilibrium clumping and the removal of palindromic SNPs and confounders, 102, 176, and 14 SNPs could be used in the analyses as the instrumental variables of Vit-D, calcium, and PTH, respectively. The F statistics demonstrated that there was no bias due to weak instruments , calcium , and parathyroid hormone  using the IVW method. As shown in p > 0.05). The MR Egger intercept test showed no evidence of directional pleiotropy (p > 0.05). The results of the leave-one-out method demonstrated that the removal of SNP did not fundamentally affect the results, which indicated that the results were actually robust.As shown in p = 0.012, Beta = −0.188) while IBS was not the risk factor of Vit-D  and calcium  using the IVW method. As shown in p > 0.05). The MR Egger intercept test showed no evidence of directional pleiotropy (p > 0.05). The results of the leave-one-out method demonstrated that the removal of SNP did not fundamentally affect the results, which indicated that the results were actually robust.As shown in To the best of our knowledge, this is the first two-sample MR study to generally clarify the causal relationship among calcium, Vit-D, PTH, and IBS. Despite employing the latest large sample size and strong instruments, our MR results did not indicate the significantly causal associations of genetically predicted calcium, Vit-D, and PTH with the risk of IBS.2 = 73.2%; WMD: −28.29, 95% CI: −49.95 to −6.62, I2 = 46.6%, respectively) and QOL  of IBS patients [Researchers have been devoted to exploring the role of micronutrients in the pathogenesis and treatment of IBS ,28. A sypatients . Howeverpatients . Conside2 = 100%) [2 = 99%). The possible mechanisms for the association between IBS and osteoporosis comprise chronic inflammation, abnormal activation of the hypothalamic–pituitary–adrenal (HPA) axis, smoking, and malnutrition. When suffering from osteoporosis, the secretion of PTH was reduced to inhibit the activity of osteoclasts, thus impeding the progression of osteoporosis, which might be the plausible explanation for the relationship between IBS and reduced level of PTH.In addition, our bidirectional two-sample MR analysis identified that IBS was associated with a lower level of PTH, although there was no causal effect of PTH on IBS. The main function of PTH is to increase the concentration of serum calcium and decrease the concentration of serum phosphorus by impacting its primary target organs of bone and kidney, so as to regulate the homeostasis of calcium and phosphorus in vivo. It was noteworthy that recent studies suggested an increased risk of osteoporosis and osteoporotic fracture for IBS patients. A systematic review and meta-analysis including four cohorts and one cross-sectional study with 526,633 participants indicated that IBS patients had a remarkably higher risk of osteoporosis than the non-IBS subjects  . MoreoveTo our knowledge, this is the first study to elucidate the causal correlation among calcium, Vit-D, PTH, and IBS from the perspective of genetic variants using a bidirectional two-sample MR approach. This method could greatly circumvent the possible impacts of reverse causation and residual confounding factors, such as incomplete adjustment for confounders, the absence of high-quality evidence, and relatively small sample sizes of trials. Additionally, we performed several sensitivity analyses to strengthen the robustness of our results.However, there are some limitations associated with this study. Firstly, the study mainly analyzed the European participants enrolled in the GWAS biobank; hence, the results could not precisely reflect the fact of patients from other regions and races. Secondly, we failed to accomplish the sex-specific, IBS subtype-specific, age-specific, and race-specific analyses due to a lack of data. Lastly, MR analysis possesses some inherent shortcomings, making it impossible to eliminate the effects of confounding factors and horizontal pleiotropy.In conclusion, the present study provides no evidence that calcium, Vit-D, and PTH are causally associated with IBS, and it suggests a lower concentration of PTH in IBS subjects. Our findings may reduce possible expenses and research interests in elucidating the effects of calcium, Vit-D, and PTH on IBS. More importantly, further research is needed to investigate the causal relationship between micronutrients and IBS.


Oxidative stress (OS) and inflammation are known to play an important role in chronic diseases, including cancer, and specifically colorectal cancer (CRC). The main objective of this study was to explore the diagnostic potential of OS markers in patients with CRC, which may translate into an early diagnosis of the disease. To do this, we compared results with those in a group of healthy controls and assessed whether there were significant differences. In addition, we explored possible correlations with the presence of tumors and tumor stage, with anemia and with inflammatory markers used in clinical practice. The study included 80 patients with CRC and 60 healthy controls. The following OS markers were analyzed: catalase (CAT), reduced glutathione (GSH) and oxidized glutathione (GSSG) in serum; and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and F2-isoprotanes in urine (F2-IsoPs). Tumor markers (CEA and CA 19.9), anemia markers  and inflammatory markers  were also determined. Comparison of means between patients and controls revealed highly significant differences for all OS markers, with an increase in the prooxidant markers GSSG, GSSG/GSH ratio, 8-oxodG and F2-IsoPs, and a decrease in the antioxidant markers CAT and GSH. Tumor and inflammatory markers (except CRP) correlated positively with GSSG, GSSG/GSH ratio, 8-oxodG and F2-IsoPs, and negatively with CAT and GSH. In view of the results obtained, OS markers may constitute a useful tool for the early diagnosis of CRC patients. Colorectal cancer (CRC) is a very prevalent tumor and one of the main causes of cancer-related death in industrialized countries, according to data from Globocan 2020 . It is nThe five-year survival rate for people with colorectal cancer is 65%, though it can vary depending on several factors, particularly tumor stage. The degree of invasion of a patient’s tumor is the most important factor in determining the stage of CRC (TNM classification), and varies from carcinoma in situ (stage 0) to distant extension of the tumor to different parts of the body (stage IV). The five-year survival rate of people with localized stage colorectal cancer is 91%, but only approximately 37% of patients are diagnosed at this early stage. If the cancer has spread to distant parts of the body, the five-year survival rate is 15% [Reactive oxygen species (ROS) are generated by the biochemical redox reactions that occur as a part of normal cell metabolism, but high doses and/or inadequate elimination of ROS result in oxidative stress (OS), which can cause severe metabolic malfunctions and cell damage . High leOS and inflammation are known to play an important role in chronic diseases, including cancer ,7,8, andIn the genome, guanine (G) is highly susceptible to OS due to its lower redox potential. A typical lesion formed under oxidative conditions is 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), a mutagenic base. If not repaired adequately, 8-oxodG can pair with adenine (A) to cause GC > TA transversion mutations . In thisF2-IsoPs, cyclic peroxides of the eicosanoid family, are a product of the oxidation of essential fatty acids composed by 20 carbon atoms, and are isomers of prostaglandins. However, unlike prostaglandins, which are produced as a direct action of the enzyme cyclooxygenase, F2-IsoPs are a final product of the peroxidation of essential fatty acids (mainly arachidonic acid) induced by ROS. These molecules are both biomarkers and mediators of OS in numerous disease settings ,15.In physiological conditions, antioxidant systems exist in equilibrium with pro-oxidant systems. Protective antioxidant mechanisms include catalase (CAT) and the glutathione system. Physiologically, CAT plays a fundamental role in the detoxification of hydrogen peroxide produced by some enzymes located in peroxisomes, such as amino-oxidase. In cells, glutathione is generally found in a reduced state (GSH) and, to a lesser extent, in an oxidized state (GSSG). This is a result of the glutathione reductase enzyme reducing GSSG back to GSH. The enzyme is constitutively active and inducible in OS situations. Some studies of CRC have reported a decrease of GSH ,17 and aSeveral reports have documented the importance of OS as a major etiological factor in colorectal carcinogenesis and the role of antioxidants in countering OS and preventing the occurrence of CRC. However, few studies to date have linked OS levels to common clinical markers of tumor progression. We hypothesized that pro-oxidant markers are increased and antioxidant markers are decreased in CRC patients with respect to healthy controls. Therefore, we set out to assess OS markers in patients with CRC and to compare them with those in a group of healthy controls. In addition, we explored possible correlations of OS markers with the presence of tumors, with anemia and with inflammatory markers currently used in clinical practice. We also analyzed OS marker values according to tumor stage with the purpose of obtaining information that could aid early diagnosis of the disease.This study included a total of 80 patients with CRC and 60 controls. Significant differences were observed between the two groups in terms of weight and height, and, consequently, in body mass index (BMI) and age. Thus, a univariate analysis of variance was performed with BMI and age as covariates, in order to eliminate potentially confounding effects . CRC patients displayed significantly higher levels of glucose, albumin, transferrin and IL-6, and lower total cholesterol, HDL-cholesterol, LDL-cholesterol, ferritin, iron and transferrin saturation index than controls. However, no differences were detected regarding creatinine, urea, glomerular filtration, triglycerides or proteins. Although significant differences in all the parameters of iron metabolism and hemoglobin were observed between CRC patients and controls, values of hemoglobin, hematocrit and MCV did not indicate the presence of anemia. In addition, iron metabolism was altered among our patients, with a lower iron, ferritin and transferrin saturation index in 52.5% of patients versus controls. In terms of inflammatory profile, significant differences were observed between the two groups in all markers, except for lymphocytes and C-reactive protein (CRP). In addition, levels of CEA and CA 19.9 tumor markers were significantly higher in CRC patients vs. controls. A total of 24 patients (30%) presented elevated levels of CEA and 14 patients (17.5%) presented elevated levels of CA 19.9.The means of the OS markers differed significantly between the control group and CRC patients, even after adjustment for age and BMI covariates. Serum CAT and GSH levels were significantly lower in CRC patients with respect to controls . ConversThe degree of invasion of the patient’s tumor was classified according to the TNM system. The number of patients per TNM stage was as follows: Stage 0: 8 (10%); Stage I: 17 (21.3%); Stage II: 20 (25%); Stage III: 26 (32.5%) and Stage IV: 9 (11.3%). These stages were regrouped for the correlation study into qualitative variables 0, 1 and 2. Thus, the patient tumors were distributed as follows: localized (Stage 0) = 44 patients (55.7%); progressive (Stage 1) = 26 patients (32.9%); and invasive (Stage 2) = 9 patients (11.4%).We explored possible associations of the biochemical, anemia and inflammation markers with tumor stage, but found none, with the exception of ferritin, which was considerably higher in stage 2 than in stages 0 and 1 .Although CEA increased in stage 2 compared to stages 0 and 1, the difference was not significant. In contrast, the increase in CA 19.9 did show significant differences in stage 2 .When OS markers were analyzed according to tumor stages, significant differences were observed in all cases, particularly in stage 2 (advanced). CAT and GSH were significantly lower in stage 2 than in stages 0 and 1, while levels of GSSG, 8-oxodG and F2-Isoprostanes, and GSSG/GSH ratio, were far higher in stage 2 than in stages 0 and 1 .The correlation analysis revealed that both TM CEA and CA 19.9 correlated negatively with CAT and GSH and positively with GSSG, GSSG/GSH ratio, 8-oxodG and F2-IsoPs. N/L ratio, platelets, fibrinogen and IL-6 correlated with all the OS markers, while CRP did not correlate with any marker. In contrast, the anemia markers did not correlate with OS markers . Our data indicate that the means of all the OS markers analyzed differed in a highly significant manner between CRC patients and controls. This difference remained significant after adjustment for age and BMI, which was surprising given that OS is reported to increase in obesity ,20,21. TVarious enzymes are responsible for eliminating excess ROS formation in cells. Cecerska-Heryće et al. studied antioxidant enzymes in CRC patients and reported an increased expression of superoxide dismutase (SOD), while the expression of CAT, glutathione reductase and glutathione peroxidase was decreased .In line with our results, decreased CAT levels have previously been reported in serum and tumor tissue in colon adenocarcinomas and other cancers ,24,25. IIn general, any condition associated with excess ROS can result in a drop of serum GSH levels. In line with the present results, Baltruskeviciene et al. , in a stExcessive ROS production causes damage to ADN and can initiate the carcinogenesis process in several types of cancer ,30. AnotF2-IsoPs are considered by some authors to be the most reliable markers for monitoring OS in vivo, due to their high chemical stability and sensitivity to OS ,38. IndeAlthough elevated levels of both TM CEA and CA 19.9 are generally used in prognosis in clinical practice , a compaThe tumor microenvironment, which is composed of macrophages, neutrophils and fibroblasts, plays a significant role in cancer progression . In thisIn addition, the activation of inflammatory interleukins, such as IL-1 and IL-6, and the overexpression of membrane proteins, such as MAP17, play an important role in the development of chronic inflammation and its potential progression to cancer . IL-6 was the best marker of inflammation in our patients, as it was higher in more than half of them  and correlated with all the OS markers analyzed. When the mean baseline of our patients was compared with that of our healthy controls, the difference proved to be significant. This is consistent with the results of other researchers who have reported that IL-6 signaling contributes to CRC development and is a predictor of poor prognosis in CRC patients ,49,50. IWe observed that inflammatory markers such as fibrinogen, platelets, neutrophils, leukocytes, N/L index and IL-6 correlated with all the OS markers analyzed. In contrast, CRP did not correlate with any OS marker. This is in line with several studies that have shown a lack of association of CRP levels with CRC risk or survival ,51,52. Anemia, defined as a decrease in hemoglobin in the blood, is a systemic inflammatory reaction and a hematological paraneoplastic syndrome due to tumor-generated substances that mimic or block normal endocrine signals for the development of the hematological lineage . Mean heSeveral reports have related increased OS in CRC patients with a worse prognosis, especially in advanced stages ,56,57. AOther authors have studied the relationship of dietary, constitutional and genetic factors and different markers with tumor stage in CRC patients. Bomfim Gomes Campos et al. analyzed the association of inflammatory, anthropometric, functional and oxidative markers (MDA) with tumor stage in newly-diagnosed CRC patients and concluded that IL-6 and triceps skinfold were indicators of cancer stage. However, the study had several limitations; it was based on only 28 CRC patients, who were divided into two groups—I (Stages 0-III) and II (Stage IV)—and a healthy control group was not included .In summary, the OS markers we have evaluated presented significant differences between CRC patients and controls, with lower levels of the antioxidant markers CAT and GSH, and higher levels of the pro-oxidant markers GSSG, 8-oxodG and F2-IsoPs, in the former when compared to the latter. Furthermore, in our CRC patients, the level of oxidation was higher in advanced stage 2 than in the more localized stages, which also suggests a strong relationship between OS and CRC. These results, together with the convenience of sample collection in the case of 8-oxodG and F2-IsoPs, endorse OS markers as a useful tool for the early diagnosis of CRC. Future studies measuring gene and protein expression in peripheral blood mononuclear cells or tumor tissue would undoubtedly complement our results.This was a longitudinal and prospective, observational study in patients diagnosed with colorectal tumor and who were candidates for tumor resection surgery and/or chemo-radiotherapy treatment at the General and Digestive Surgery Service of University Hospital Dr. Peset. A control group of age-matched healthy volunteers was included for comparison. A flow chart of the study protocol is provided as The study was designed in accordance with the principles of ethics of the Declaration of Helsinki , and was evaluated and approved by the Clinical Research Ethics Committee of University Hospital Dr. Peset. Informed consent was obtained from all the subjects involved in the study.A total of 80 patients with a diagnosis of colorectal tumor (both advanced adenomas and carcinomas) were enrolled in the study between March 2019 and January 2020. Advanced adenomatous neoplasia was confirmed when polyps reached 1 cm or more in diameter and had a villous component or high-grade dysplasia.Patients of both genders, without comorbidities, and who had not received radiotherapy or chemotherapy, were eligible for inclusion in the study. CRC patients with systemic or autoimmune diseases , or lung, thyroid, liver, kidney, gastrointestinal or infectious diseases , were excluded. Smokers and patients who had taken drugs  in the previous three months were also excluded from the study. In addition, patients who did not want to participate voluntarily in the study and those whose health could be compromised during the study due to advanced age or poor general health were excluded.2, with clinical characteristics similar to those of the CRC patients, and no clinical pathologies  were included in the study.As a control population, 60 healthy subjects of both genders, with a BMI < 30 kg/mSerum samples were extracted after 12 h fasting and collected in dry 10 mL tubes with a silicone gel separator and coagulation accelerator. Following clot retraction  the samples were centrifuged at 3500× rpm for 5 min in a Rotina 380R Hettich centrifuge . Aliquots were separated from the serum for determination of OS markers, and a volume of 1 mL was retained for biochemical determinations, which were performed on the same day. The aliquots were frozen at −80 °C in the New Brunswick Scientific Premium U 410 freezer  until assays were performed.A basic clinical analysis plus a study of ferric metabolism, inflammation markers and TM were requested for each serum sample. Metabolites were analyzed in an automated chain of Architect C16000 equipment from Abbott  and in the Cobas 6000 from Roche Diagnostics , in accordance with the spectrophotometric and immunochemical methodology of the manufacturers.Analysis of biochemical parameters, including triglycerides, total cholesterol and HDL cholesterol, glucose, total proteins, albumin, urea, creatinine and electrolytes, was performed with automatic analyzers following standard procedures. Validation of appropriate internal controls was performed on every workday.The glomerular filtration rate was estimated by means of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), a mathematical formula that includes serum creatinine, age, sex and race as variables.For the hematimetric analysis, samples of whole blood were collected in EDTA-K3 tubes and assessed with a Beckman-Coulter LH 500 hematology analyzer . For fibrinogen analysis, samples of whole blood were collected in sodium citrate tubes and assessed with an ACL-TOP of Instrumentation Laboratory Company .For determination of OS markers, Cayman Chemical  spectrophotometric assays were employed, except for 8-oxodG, which was determined by High Performance Chromatography with Electrochemical Detection (HPLC-EC). A 515 HPLC Waters Pump  with ESA Coulochem II electrochemical HPLC detector  was also employed.CAT, GSH, GSSG and GSSG/GSH ratio were determined in serum, and 8-oxodG and F2-IsoPs in morning urine samples (the results were corrected with urinary creatinine to eliminate variability in the concentrations of the urine samples).TM and IL-6 were determined by electrochemiluminescence using a Cobas 6000 from Roche Diagnostics . CRP was performed by spectrophotometry in the automated chain of Architect C16000 equipment from Abbott . t test for parametric samples or a Mann–Whitney U test for nonparametric samples. Spearman’s correlation coefficients were employed to measure the strength of the association between OS, tumor, anemia and inflammatory markers. Statistical analysis was performed with the Statistical Package for the Social Sciences (SPSS), version 17.0 for Windows . The results of the continuous quantitative variables are expressed as means and standard deviation in the tables, and means and standard error of means in the figures. The Kolmogorov–Smirnov test was used to assess normality for continuous variables, and the data conformed to normal distribution patterns. The differences in means between the control group and CRC patients were compared using a Student’s p < 0.05.To perform the statistical analysis of potential associations of the different variables with tumor stage, the AJCC TNM stages were redefined as qualitative variables 0, 1 and 2, as follows: tumors located in the colon/rectum, including TNM stages 0, I and II = Stage 0; progressive  tumors with lymph node involvement, TNM stage III = Stage 1; and invasive (advanced) tumors, with distant metastasis or distant peritoneal sites, TNM stage IV = Stage 2. A one-way analysis of variance-ANOVA for independent samples was performed, followed by the Student–Newmann–Keuls (SNK) post hoc test to determine the mean difference of the studied markers between stages. In this case, we used Levene’s test to assess the equality of variances for parametric variables and the Kruskal–Wallis test for non-parametric variables. The level of statistical significance used in all cases was α, with significant differences confirmed when


Although various neuropsychiatric symptoms are frequently accompanied with Alzheimer’s disease (AD) and pose a substantial burden to both patients and caregivers, their neurobiological underpinnings remain unclear. This study investigated associations between regional cerebral blood flow (rCBF) and neuropsychiatric symptom domains in early AD. A total of 59 patients with early AD underwent brain technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) scans. Neuropsychiatric symptoms were assessed by the Neuropsychiatric Inventory and clustered into the affective, apathy, hyperactivity, and psychotic domains. A voxel-wise multiple regression analysis was performed with four domain scores as independent variables and age, sex, and Mini-Mental State Examination scores as covariates. The affective domain score was negatively correlated with rCBF in the prefrontal cortex, thalamus, and caudate. The apathy domain score showed inverse correlations with rCBF in the prefrontal and pre/postcentral gyri and midbrain. Patients with higher hyperactivity domain scores had increased rCBF in the prefrontal and temporal lobes. The psychotic symptom domain was positively correlated with rCBF in the cuneus and negatively associated with rCBF in the prefrontal, cingulate, and occipital regions and putamen. The score of each neuropsychiatric symptom domain showed the differential correlates of brain perfusion, while altered rCBF in the prefrontal cortex was found in all domains. Although preliminary, our results may suggest common and distinct patterns of rCBF underlying neuropsychiatric symptoms in early AD. Further studies with larger samples and control participants are warranted to confirm these findings. Alzheimer’s disease (AD) is the leading cause of dementia and has become a cause of major medical, social, and economic burdens. Besides cognitive impairment, neuropsychiatric symptoms (NPSs) are also important characteristics of Alzheimer’s disease (AD), since one or more of these symptoms have been known to develop in more than 80% of patients during the course of AD . NPSs caSeveral neuroimaging studies using various modalities have investigated the brain mechanisms of NPSs in AD ,7,8,9. MThis study evaluated associations between rCBF and severity of NPS domains in patients with early AD using single-photon emission computed tomography (SPECT). Based on previous neuroimaging studies ,7,8,9, wPatients with early AD who visited the dementia outpatient clinic at Incheon St. Mary’s Hospital  were enrolled according to the following inclusion criteria: (1) diagnosis of AD according to the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA) and the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria; (2) a score of 0.5 in the Clinical Dementia Rating (CDR); (3) a score greater than or equal to 1 on the Neuropsychiatric Inventory (NPI); and (4) participation in brain SPECT scans. The exclusion criteria were as follows: (1) a history of stroke, head trauma, epilepsy, or cerebrovascular disease including small vessel disease based on magnetic resonance imaging (MRI); (2) a history of mixed or vascular dementia; or (3) a history of other psychiatric or neurological disorders. The study protocol was approved by the Institutional Review Board of the Incheon St. Mary’s Hospital. Informed consent was waived for this retrospective analysis.The clinical assessments, including a medical history and neurological examinations, were conducted by the neurologists. Cognitive status was assessed using the Mini-Mental State Examination (MMSE). The stages of dementia were determined using the Clinical Dementia Rating (CDR).Twelve NPSs—delusions, hallucinations, agitation, depression, anxiety, apathy, irritability, euphoria, disinhibition, aberrant motor behavior, sleep disturbances, and eating abnormalities—were assessed using the NPI. The total score for each of the 12 symptoms, with a range of 0 to 12, is calculated by multiplying the severity scores (from 0 to 3) with the frequency scores (from 0 to 4). The scoring was based on the responses to the questions by the patient’s caregiver.According to the previous factor analysis study on a large sample of AD patients , twelve 3, matrix = 128 × 128 mm2, field of view = 250 × 250 mm2, 20% symmetric energy window at 140 keV). The standard ordered subset expectation maximization (OSEM) algorithm (6 iterations and 10 subsets) was performed with a Butterworth filter  to reduce noise.Brain SPECT scans were acquired using a dual-headed gamma camera , which was equipped with a low-energy fan-beam collimator. After being injected with 555–740 MBq of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO), patients were rested for 40 min before scanning. While scanning, patients were in a supine position with their eyes remaining open. Images were obtained as the camera was rotated for a total of 720°, with intervals of 6 degrees, at a rate of 12 s per frame. Reconstruction of continuous transaxial images was performed . First, the images were spatially normalized to the standard SPECT template. Then, the images were resliced with a voxel size of 2.0 × 2.0 × 2.0 mme region . For a vA total of 59 patients  with early AD (CDR stage of 0.5) were included in this study. Mean MMSE and CDR sum of boxes scores were 20.5 ± 3.6 and 2.4 ± 1.3, respectively. The frequencies and mean scores for the NPS domains and the corresponding symptoms are shown in p < 0.001), right precentral gyrus , left superior frontal gyrus , and left caudate   .p < 0.001), left midbrain , right postcentral gyrus , right medial orbital gyrus , and right precentral gyrus   .p < 0.001) and superior frontal gyrus   .p < 0.001) and inversely associated with rCBF in the right putamen , left inferior occipital gyrus , left middle frontal gyrus , left anterior cingulate gyrus , left inferior frontal gyrus , right precentral gyrus , and left central operculum   .To the best of our knowledge, this is the first study to investigate associations between the NPS domains and rCBF in patients with early AD. Using the SPECT image analysis, four different NPS domains, including the affective, apathy, hyperactivity, and psychosis domains, showed distinct patterns of altered rCBF. Specifically, the affective domain was associated with decreased rCBF in the prefrontal, precentral, and subcortical regions. The apathy domain was characterized by decreased rCBF in the prefrontal, pre/postcentral, and midbrain areas. Increased rCBF in the prefrontal and temporal cortices was involved in the hyperactivity symptom domain. Lastly, altered rCBF in the prefrontal, cingulate, precentral, opercular, occipital, and subcortical regions was associated with the psychosis symptom domain. Particularly, it is noteworthy that abnormal rCBF in the prefrontal cortex was implicated in all NPS domains.The affective domain showed negative correlations with rCBF in the superior frontal and precentral gyri, thalamus, and caudate. Previous studies have provided converging evidence that dysfunction and atrophy of the cortico-striatal-pallidal-thalamic circuits may, in part, account for the pathophysiology of major depressive disorder (MDD) . This ciHigher apathy domain scores were associated with lower rCBF in the superior frontal, orbitofrontal, and pre/postcentral gyri and midbrain in our study. Consistent with our findings, decreased rCBF, hypometabolism, and atrophy of the superior frontal and orbitofrontal gyri have been consistently found in AD patients with apathy ,7. MoreoIn the current study, the hyperactivity symptom domain was positively correlated with rCBF in the superior frontal and inferior temporal gyri that are implicated in inhibition of impulsive thoughts and visual processing of negative emotions, respectively ,29. The In our study, AD patients with greater severity of psychosis symptoms showed decreased rCBF in the frontal, anterior cingulate, putamen, opercular, and inferior occipital regions and increased rCBF in the cuneus. In line with this, reduced rCBF, hypometabolism, and gray matter atrophy of the dorsolateral, inferior frontal, and anterior cingulate gyri have been consistently reported in AD patients with psychosis ,8,13. Inp < 0.01 for the voxel-wise multiple regression analysis to examine correlations between cerebral glucose metabolism and NPS domain scores in early-onset AD [The following limitations should be considered when interpreting the results of this study. First, due to the small sample size, the findings are preliminary and further larger studies are warranted to confirm the associations between NPSs and rCBF in AD. Second, as the control participants were not included in the analysis, our study demonstrated positive or negative correlations between NPSs and rCBF in the patients with both AD and NPSs. The alterations in rCBF should be compared between AD patients with NPSs and those without NPSs or healthy controls in future studies. Third, this study focused on patients with early stages of AD, considering the effects of AD pathology on cerebral perfusion. To generalize our findings, future studies including patients with various severities of AD symptoms are required. Fourth, as multiple comparison correction was not applied in the analysis, further studies with more stringent thresholds may reduce the possibility of false positives. However, a previous positron emission tomography study also used the liberal threshold of uncorrected onset AD .In summary, each NPS domain score showed differential correlates of brain perfusion, while altered rCBF in the prefrontal cortex was found in all domains. Our results may suggest common and distinct patterns of rCBF which underlie NPSs in early AD. Future studies using multimodal neuroimaging techniques will further broaden our understanding of the neurobiological mechanisms underlying NPSs in AD. In addition, longitudinal studies are needed to reveal the progression of rCBF deficits and associated NPSs.


The present review aimed to draw a conclusion regarding changes in the human brain in both unacclimatized and acclimatized states in a natural HA environment. Using multiple advanced analysis methods that based on MRI as well as electroencephalography, the modulations of brain gray and white matter morphology and the electrophysiological mechanisms underlying processing of cognitive activity have been explored in certain extent. The visual, motor and insular cortices are brain regions seen to be consistently affected in both HA immigrants and natives. Current findings regarding cortical electrophysiological and blood dynamic signals may be related to cardiovascular and respiratory regulations, and may clarify the mechanisms underlying some behaviors at HA. In general, in the past 10 years, researches on the brain at HA have gone beyond cognitive tests. Due to the sample size is not large enough, the current findings in HA brain are not very reliable, and thus much more researches are needed. Moreover, the histological and genetic bases of brain structures at HA are also needed to be elucidated.With the advancement of  High altitude (HA) is characterized as having lower atmospheric oxygen pressure, a cold climate, and strong ultraviolet rays, and is therefore inhospitable to human settlement. However, there are still a large number of people living in HA regions. More than 10 million highlanders permanently reside above 2,200 m in the Qinghai-Tibet Plateau . Every y2 and pH may have direct effect on cerebral blood flow. Hypobaric and cold may be the other two important factors contributing to the alteration of the brain at HA. Aggravation of mental illness  were reported in groups of 26 and 21 mountain climbers ascending to altitudes of 7,000 and 8,000 m , 1996 anIn recent years, GM and WM structural changes in individuals at HA have been examined based on brain T1 MRI and diffusion tensor imaging (DTI), respectively  for 30 days  and at MRegional GM changes were seen in the mountain climbers who repeated expeditions to Mount Everest , adult sFor HA immigrants, the increase in GM may be associated with hypoxia-induced neurogenesis, gliogenesis, or vascular proliferation. Adult neocortices, such as the prefrontal cortex, inferior temporal cortex, and posterior parietal cortex, have the capability of neurogenesis , which mFew studies have observed changes in brain WM at HA. The change in total WM volume varies, as seen by increases after people stayed at 4,300 m for either 30 days  or 6 dayp = 0.005), which may squeeze ventricle, and result in CSF volume reduction. In contrast, in the study of p = 0.012), which may cause the ventricles to expand. In the observation of The change in cerebrospinal fluid (CSF) volume also varies, with CSF volume showing decrease, increase, or no change. In the study conducted by In a recent study, the modulation of HA adaptive genetic variants (single nucleotide polymorphisms [SNPs]) of EGLN1, EPAS1, and PPARA on the organizational network of the brain was investigated in Tibetan natives in the Qinghai-Tibet Plateau. The study showed that the HA adaptive genetic variants regulated the topological organization of large-scale structural brain networks . These fIron is the most abundant transition metal found in the human brain, and is highly compartmentalized in subcortical nuclei. Iron plays an important role in the physiological functions and development of human brains . MRI stuDetailed information is shown in Event-related potentials (ERPs), obtained by time-locked averaging EEG, have been used to evaluate the electrophysiological processing of cognitive activity in various HA residents. Most studies of ERP use task-activated electrode points in the relevant brain regions for analysis, called regions of interest analysis which can control class I errors in statistical testing and better discernment of the effects of high altitude exposure on specific brain functions. Given the high temporal resolution, ERPs have been used to record the precise temporal sequence of brain processes. The onset of stimulation is shown to evoke a characteristic negative potential (N1) of ERP with a peak latency around 120 ms and is used as index of the attentional allocation of the early visual processing . NegativEarlier EEG studies mainly tested the electrophysiological processing of visual stimuluses after short-term exposure to HA. Two previous studies have observed EEG patterns during exposure to HA-induced hypoxia over time. One study found that the occipital alpha component was 25.5% at sea level, which changed at 3,500 m to 45.7, 15.8, 28.0, 30.3, and 33.2% on days 2, 7, 14, 21, and 28, respectively. The average amplitude was 17.3 μV at sea level, which changed at 3,500 m to 23.3, 11.8, 16.2, 17.3, and 19.8 μV on days 2, 7, 14, 21, and 28, respectively. These results indicate a cortical depression in the initial phase of HA exposure, followed by a gradual build-up of EEG waves during acclimatization . AnotherRecently, serial task-induced ERPs were measured in immigrants who had lived at Lhasa (3560 m) for more than 2 years. The HA immigrants showed reduced attentional resources with smaller P3 amplitudes , reducedRare electrophysiological studies of brain function were conducted on HA natives. In Bolivian children living at 3,700 m, reductions in the amplitude of delta and beta frequencies were recorded . In TibeGiven its high spatial resolution, functional magnetic resonance imaging (fMRI) is used to measure changes in blood dynamics caused by neuronal activity. In fMRI, the blood oxygenation level dependent (BOLD) effect is employed to identify and delineate neuronal activity. An initial fMRI study was conducted on individuals who stayed at Chacaltaya  for 5 weeks, and showed that the average magnitude of BOLD responses induced by visual stimulation was reduced in the occipital gyrus . SubsequOne study showed decreases of neuronal co-activation within the left/right frontoparietal network, sensorimotor network, and auditory network at resting state in lowland students after they had their college study at Lhasa for 2 years . AnotherThe regions of the brain found to be altered in the HA population included the bilateral insular cortex, occipital cortex, cingulate cortex, precentral gyrus, and hippocampus as well as cerebellum  In MRI experiments, data acquisition and analysis are required to be carried out by different researchers; however, due to the limited conditions in the actual research (these data collection are difficult), some studies may not be double-blind. However, seeing that these results are relatively consistent, we suggest that the factor of human expectation is small. Insular cortex is the visceral sensory center, which can be expected to be affected by hypoxia, but the changes in the visual and motor cortices cannot be expected. Generally speaking, we think the results are relatively reliable. (2) VBM involves a voxel-wise comparison of the local concentration of GM between groups. Corrections for multiple comparisons are needed to avoid statistical class I errors. The results showed in some researches, however, cannot stand correction. With or without correction, similar HA exposure showed different results in different studies. For example, to study the effect of 2-year HA exposure on human brain, There are still many questions that need to be answered, such as which mechanisms, neuronal, glial, and/or vascular, contribute to brain structure alterations? Exploring the genetic basis of brain structures in HA natives helps to understand the mechanisms of HA adaptation in the native population. The difference that exists between individual brains in response to HA is also an interesting issue. How about brain readaptation to lowlands after HA immigrants return to lowlands?According to literature, there are several strategies that may be employed to protect brain injury in HA environment. (1) Cerebral edema contributes much to the severity of the ultimate brain damage. Gradual ascents are proven to be the best strategy for preventing HA cerebral edema . MoreoveXZ: investigation and writing—original draft. JZ: conceptualization, writing—review and editing, and funding acquisition. Both authors contributed to the article and approved the submitted version.


Baccharis juncea, Juncus balticus, and Schoenoplectus americanus), transitional hygrophiles , and their various combinations. We detected compositional differences among the soil surface microbiota associated with each plant formation in the sampling area. There were changes in soil microbial phylogenetic diversity from the strict to the transitional hygrophiles. Moreover, we found alterations in the abundance of bacterial phyla and genera. Halobacteriota and Actinobacteriota might have facilitated water uptake by the transitional hygrophiles. Our findings helped to elucidate the microbiota of Salar de Atacama and associate them with the strict and transitional hygrophiles indigenous to the region. These findings could be highly relevant to future research on the symbiotic relationships between microbiota and salt-tolerant plants in the face of climate change-induced desertification.Salar de Atacama is located approximately 55 km south of San Pedro de Atacama in the Antofagasta region, Chile. The high UV irradiation and salt concentration and extreme drought make Salar de Atacama an ideal site to search for novel soil microorganisms with unique properties. Here, we used a metataxonomic approach (16S rRNA V3-V4) to identify and characterize the soil microbiota associated with different surface azonal vegetation formations, including strict hygrophiles (IMPORTANCE The study of the composition and diversity of the wetland soil microbiota associated with hygrophilous plants in a desert ecosystem of the high Puna in northern Chile makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. These microorganisms are adapted to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration; they can be applied in various fields, such as biotechnology and astrobiology, and industries, including the pharmaceutical, food, agricultural, biofuel, cosmetic, and textile industries. These microorganisms can also be used for ecological conservation and restoration. Extreme ecosystems are a unique biological resource and biodiversity hot spots that play a crucial role in maintaining environmental sustainability. The findings could be highly relevant to future research on the symbiotic relationships between microbiota and extreme-environment-tolerant plants in the face of climate change-induced desertification. Salt flats are saline hydrogeological systems frequently associated with arid and hyperarid climates. In these regions, the water table is several centimeters to decimeters below the soil surface , 2, whic3–Wetlands are vital ecosystems with high biodiversity. Studies continue to discover new species  and new 10–Baccharis juncea, Juncus balticus, and Schoenoplectus americanus. The roots of the latter do not make direct contact with water. Rather, these plants absorb moisture via capillary action. The representative species of this plant type include Distichlis spicata, Lycium humile, and Tessaria absinthioides  aquifer. This water supply supports the development of azonal vegetation , 16, whithioides . Little thioides .Microorganisms play an important role in the regulation of ecological function of wetlands and are critical for maintaining the health of the global ecosystem. Symbiotic microorganisms are crucial for the survival of plants in these extreme ecosystems  as they 18–20–Studies on this type of microbial community have determined that certain environmental factors, such as aridity, are negatively correlated with rhizobacterial diversity and abundance . Wet andDue to the marked vulnerability of high Andean wetlands to be affected by climate change in the near future and given the limited studies on the microbiota in Tilopozo, more studies are necessary to understand the diversity of this particular site. In association with the vegetation present in the wetlands, there is a need to know and analyze the composition of the microbial communities (bacteria and archaea) present in the Tilopozo saline wetland system. In this study, the soil microbiota associated with hygrophilous-type plants is profiled: the objective is to characterize and establish the differences in the soil microbiota. We hypothesize that the composition of the microbiota presents differences in the different types of soil and is modulated by the water limitation of the soil. The present study is the first to investigate the composition and diversity of the soil microbiota associated with classes of hygrophiles indigenous to Chile.In the present study, we characterized the microbiota in the soil samples associated with plant formations in Tilopozo, Salar de Atacama, Antofagasta, Chile . In Fig.P = 0.0118) (P = 0.0112), and UniFrac  distances . We compared α-diversity indices, where pairwise comparisons were made among all formation types. The α-diversity analysis showed significant differences between the strict and transitional hygrophiles (Table S2). InvSimpson diversity was, on average, 67% higher for strict hygrophiles than for transitional hygrophiles, Shannon diversity was, on average, 7% higher for strict hygrophiles than for transitional hygrophiles, and phylogenetic diversity (PD) was, on average, 70% higher for strict hygrophiles than for transitional hygrophiles  . The β-diversity analysis revealed significant differences between the strict and transitional hygrophile formations in terms of their Jaccard  , Bray-Cu < 0.05) . Hence, Proteobacteria (31.5%), Bacteroidota (11.3%), Actinobacteriota (7.6%), Chloroflexi (7.6%), Acidobacteriota (7%), Gemmatimonadota (7%), Halobacteriota (6.9%), Firmicutes (5.2%), Methylomirabilota (3.3%), Desulfobacteriota (2%), Myxococcota (1.1%), and Nitrospirota (1%). The most abundant genera comprised uncultured bacteria belonging to the phyla Bacteriota, Proteobacteria, Actinobacteria, Halobacteriota, and Gemmatimonadota, and included PAUC43f, Halomonas, Bacillus, Marinobacter, BD2-11, Pseudomonas, S085, SAR202, Saccharospirillum, and wb1-A12  and Gemmatimonadota  were associated with the transitional hygrophiles, whereas Acidobacteriota , Bacteroidota , Proteobacteria , and others  were associated with the strict hygrophiles , namely,  wb1-A12 . The linl-alanine biosynthesis, stearate biosynthesis II, mycolate biosynthesis, palmitoleate biosynthesis, oleate biosynthesis IV, superpathway initiation of fatty acid (5Z-dodec-5-enoate) biosynthesis, 8-amino-7-oxonanoate biosynthesis I, pentose phosphate pathway (PPP), mannan degradation, and nitrifier denitrification. Five of these were overrepresented for the transitional hygrophiles, namely, reductive tricarboxylic acid cycle I, fatty acid elongation, l-lysine biosynthesis, 3-phenylpropanoate degradation, and aerobic toluene degradation IV via catechol   .In the present study, we analyzed the microbial profiles of soil samples collected from a complex and important ecosystem. We detected significant differences in the microbial compositions of the soils associated with the strict and transitional hygrophiles of Tilopozo, Salar de Atacama, Antofagasta, Chile.in vitro experiment showed drying and rewetting of the soil substantially changed the OTU diversity, indicating mortality, and compositionally altered the relative abundance of Acidobacteria, Alphaproteobacteria, Bacteroidetes, and Firmicutes . This finding indicates that there is great microbial diversity (Shannon index) in soils with strict hygrophile formation , Bacteroidetes, Chloroflexi, and Cyanobacteria , Methylomirabilota, and Firmicutes. Perhaps the presence of these phyla is due to other factors, such as elevation  and soils with high levels of UV radiation, the presence of strong oxidizing conditions, and extreme aridity . These soil samples are reported to be dominated by member of the phylum notrophs , involvenotrophs . Perhapsoxyfera”  would beThe change in microbiota composition in the mixed hygrophile zone is not surprising. Other studies have shown how the soil microbiome response differed significantly based on the vegetation coverage, such as pine forest , evergreThermoplasmatota are highly abundant marine planktonic Archaea  to understand the metabolic pathways of the rhizospheric microbiota and plants.Wetlands are important sources of biodiversity , 12, andThe greatest measure to maintain this place and continue the study of biodiversity would be the declaration of the status of Chile as a protected area. In this way, the permanence of this ecosystem is ensured; moreover, it could be free of human intervention, and the total conservation of life forms that reside here could be attained.Tilopozo in Salar de Atacama, Antofagasta, Chile, is characterized by arid, hypersaline soils, adjacent saline water bodies, and wetlands. In this extreme environment live strict and transitional hygrophile plants. We found significant differences in the microbiota compositions of the soils associated with each plant type. The observed variations in soil microbial diversity and composition among plant types may be explained by the relative differences in the hydric capacities of the soils associated with them. The rhizospheres of these plant types should nonetheless be analyzed to determine the roles of microorganisms therein. Our results demonstrated that certain microbial phyla are characteristic of each soil type and could, therefore, be used as biomarkers or associate with plants to survive. These findings provide a clue regarding relevant microorganisms in soils associated with drought or water limitations.Thermoplasmatota and Gemmatimonadota are interesting phyla that warrant further research, as they may contribute the tolerance and persistence of hygrophilic plants. However, more advanced analytical techniques must be applied to establish their functions in this extreme ecosystem. Future research should endeavor to identify factors that account for the robustness of the microbial communities of this harsh environment. To achieve this, the functions, metabolic profiles, and plant symbiotic associations of these microbial communities should be explored.The research area is the Tilopozo saline wetland system located in the southern sector of Salar de Atacama in the Antofagasta region, Chile  . The ele−1  to 223.0 dS m−1 . The lithology of the regional MNT basin contributes to the high concentrations of Ca2+, Mg2+, K+, Na+, and Cl− in the soil.The soils in Tilopozo are characterized by surface saline encrustations, concretions, and/or accumulations. However, in certain sites, water rises near or at the soil surface and supports the development of strict and transitional hygrophiles  . The soin = 4), transitional (n = 4), and mixed hygrophile formations (n = 2). In each pit, the horizons of the soil profile were identified, and then samples were collected (4 to 5 per pit). The collection by soil profile involved extraction around the roots (maximum of 3 cm) with a sterile spatula. The soil content was deposited in sterile 50-mL Falcon tubes  to three-fourths the volume. The tubes were immediately sealed to avoid environmental contamination, labeled, and stored at 4°C during transport to the laboratory.Enriched soil samples were collected from a total of 10 pits and distributed as follows: strict . A homogenizer  was operated at 40 Hz for 5 min to break the cells and release their DNA. The DNA was eluted with 100 μL of Tris buffer and stored at −20°C until further use.CCTACGGRRBGCASCAGKVRVGAAT) and reverse primers (GGACTACNVGGGTWTCTAATCC)  and delivered to Genewiz, Inc. , for genomic library preparation and 16S rRNA sequencing by paired-end MiSeq (2× 250 bp) . The genomic DNA (gDNA) libraries were generated using the MetaVx kit . The gDNA was used to generate 16S rRNA amplicons spanning the bacterial and archaeal V3 and V4 hypervariable regions. The amplicons were amplified with forward primers (CTAATCC) –104.The fastqs files supplied by the facilities were processed in QIIME2 . The reaOTU abundance, taxonomy, phylogeny, and metadata were integrated into a phyloseq object for subsequent analyses with the Phyloseq package v1.38.0 . QualityP < 0.05).The calculation of α diversity was performed in R with the function estimate_richness (Phyloseq version 1.38.0) for observed, Chao1, ACE, Shannon, Simpson, and InvSimpson indices. Phylogenetic diversity was estimated using Picante package of R (version 1.8.2) . Pairwisβ diversity  dissimilarity among samples was evaluated using principal-coordinate analysis. Each index was compared using permutational multivariate analysis of variance in the “vegan” package v2.5-7 in R  with theP < 0.05) with the “microbiomeMarker” package (v1.1.2)  was performed on the azonal species factor between the strict and transitional hygrophiles using a high-dimensional biomarker discovery algorithm  and Krus(v1.1.2)  in R (v4(v1.1.2)  in Rstud(v1.1.2) . Differe  database  under BioProject accession no.


Cardiovascular disease is a common disease with high prevalence, disability, and mortality. Exercise therapy can improve cardiac functional reserve and life quality of patients, but the benefits of different exercise intensities for cardiovascular patients are still controversial. In this study, literature search and meta-analysis were used to explore the effect of 2 intensities of exercise on the rehabilitation effect of cardiovascular patients.  We searched Embase, Wiley online library, PubMed, Science Direct, and Clinicaltrials to look for randomized controlled trial (RCT) studies of high-intensity interval training (HIIT) versus moderate continuous training (MCT). After screening the inclusion criteria for the literature and assessing the risk of bias, a software analysis was performed using the R language toolkit to obtain forest plots and funnel maps. Z = 2.12, P = 0.0344), the peak heart rate HR peak was higher than that of the MCT training , Z = 5.84, P < 0.0001), the respiratory exchange rate (maximum RER) was higher than that of the MCT training , Z = 2.36, P = 0.0184), and the quality of life was higher than that of the MCT training , Z = 2.40, P = 0.0165). Discussion. Compared with moderate continuous training, high intensity interval training is more conducive to improve the cardiopulmonary function of cardiovascular patients and improve their physical life quality. 10 articles were included in this study into the quantitative analysis, and 520 patients participated in the study; meta-analysis results showed that after HIIT intervention, the VO2 peak index of patients was higher than that of the MCT group ,  Cardiovascular disease is a heart blood vessel disease with the characteristics of high prevalence, disability rate, and mortality, which is an ischemic or hemorrhagic disease of the systemic tissues and heart caused by atherosclerosis, blood viscosity, hyperlipidemia, and hypertension. Cardiovascular disease is a common disease in the elderly over 50 years of age and a serious threat to the health of the elderly . Exercishttp://Clinicaltrials.org also has been searched. We set the search time to the database under construction to December 2021 and searched with the keyword combination  & (moderate continuous training|MCT) & (heart).We used a computer to search the literature in Embase, Wiley online library, PubMed, and Science Direct databases. Moreover, clinical experimental research in 2peak), peak heart rate (HRpeak), and maximum respiratory exchange rate (maximum RER) before and after the intervention need to be recorded in detail in the literature. Other aerobic exercise indicators may appear in the literature, but we will not make statistics. Other indicators such as adverse reactions to exercise and quality of life will be included in the statistics as secondary outcome indicators. Since the scales used for evaluating the quality of life are inconsistent in literature, we only selected the physical scores in the scales for comparison(1) We only included randomized controlled trials (RCTs), the language is English, and RCTs are a means of testing the effects of a therapy or drug in health care, which is often considered the gold standard in clinical evidence. (2) All patients with cardiovascular disease, we have no restrictions on age, the disease types include acute (chronic) coronary heart disease, angina, arrhythmia, heart failure, and the causes of which are hypertension, hyperlipidemia, and atherosclerosis . (3) Int(1) We excluded patients with severe heart disease (requiring bed rest), patients who were not suitable for immediate exercise after cardiovascular surgery, and patients with paralysis and musculoskeletal diseases who could not perform aerobic exercise; we excluded patients with only cardiovascular disease tendency (but no disease), such as diabetic patients, hypertensive patients, and severely obese patients; we also excluded studies with healthy subjects. (2) Patients with detailed description of intervention frequency and intervention methods will be excluded. (3) Patients with the nonrandomized controlled study will be excluded, and we also excluded all pilot study, cause the sample size included in the study is too small. (4) Patients lacking outcome indicators, or the data cannot be transformed into studiesAll documents are imported into the software (Endnote X9) after the literature search and duplicate documents are excluded. 2 researchers read the title and abstract for further screening. If the original text is unavailable on the Internet, contact the author of the original text. 2 researchers cross-checked the results of their respective screens, and if there were inconsistencies, they were resolved after discussion and a third person could be introduced for discussion if necessary.We used the Joanna Briggs Institute Evidence-Based Health Care Center (JBI) in Australia  to evalu2 researchers independently extracted literature data: patient age, patient nationality, gender ratio, height, weight, disease, medication, grouping characteristics, number of grouping samples, and exercise intervention characteristics . Two researchers cross-examined the results after data extraction and discussed the resulting differences.R language toolkit R Version 4.1.2  was used as the analysis tool, and Meta package was loaded before software operation; (2) continuous variables take the inverse variance statistic, and mean difference (MD) and 95% CI were used to report statistics; (3) descriptive statistics of forest maps and comparisons; (4) I2 analysis and Q validation were used for literature heterogeneity, I2 > 50% or P < 0.1 was used to indicate heterogeneity of results, random-effects model was used to obtain OR values; otherwise, fixed effects were used to obtain OR values; (5) heterogeneity analysis shows that there is heterogeneity between the literature, and the source of heterogeneity needs to be investigated using a case-by-case exclusion method, which is generally described when the source of heterogeneity cannot be determined; (6) software's Meta inf command is used for sensitivity analysis; (7) funnel plot was used to represent publication bias, and metabias command of the software was used for quantitative analysis of publication bias(1) The flowchart of literature selection was shown in 10 studies were included in this study. 5 studies were conducted on patients with coronary heart disease, and 5 studies were conducted on patients with heart failure, as shown in All studies , 10–17 wI2 = 78%, P < 0.01). Random effect model was used. Meta-analysis showed that VO2peak index in patients after HIIT intervention was higher than that in MCT group , Z = 2.12, P = 0.0344).All studies , 10–17 rZ = 2.07, P = 0.0433) and  . There still has heterogeneity in the internal studies. The statistics of VO2peak index after the 2 interventions were ( 0.0297) .I2 = 32%, P = 0.20). The fixed-effect mode was used. Meta-analysis indicated that the HRpeak of patients after HIIT training was higher than that after MCT training , Z = 5.84, P < 0.0001)  .I2 = 0%, P = 0.63). The fixed effect mode was used. Meta-analysis showed that the respiratory exchange rate (maximum RER) of patients after HIIT training was higher than that after MCT training , Z = 2.36, P = 0.0184), as shown in 9 studies , 11–17 rI2 = 57%, P = 0.07). The random-effects model was used. Meta-analysis indicated that the quality of life of patients after HIIT training was higher than that after MCT training , Z = 2.40, P = 0.0165)  .It was reported in the studies , 14, 17 I2 = 79%, P < 0.01). After the studies were divided into 2 subgroups according to disease types, the internal heterogeneity was not eliminated. We speculated that the existence of heterogeneity may be related to multiple factors such as patient age level, disease type, and difference in intervention methods.Analysis of the VO2 peak index and quality of life index shows statistical heterogeneity between the literature (meta Influence showed good stability (good sensitivity) of the results, as shown in Influence factor analysis using Metabias resulted in t = 0.75, df = 8, P value = 0.4748, and P > 0.05 suggesting no publication bias.In the analysis of VO2peak index, the funnel plot shows that the data are basically evenly distributed and the publication bias is small, as shown in 10 RCT studies were in this study. 1 “level A” study was evaluated by JBI methodology, and the other 9 were all level B. The main reason why 9 articles were rated as level B was the concealment of literature description allocation, which may cause the imprecise design of study protocol and finally the risk of implementation bias.Meta-analysis results showed that the peak oxygen consumption of cardiovascular patients after HIIT exercise intervention was higher than that of MCT exercise, the peak heart rate and respiratory exchange rate of patients were higher than the MCT exercise, and the quality of life of patients after HIIT exercise was higher than that of MCT exercise. Maximum oxygen consumption, peak heart rate, and respiratory exchange rate can reflect the pumping function and cardiopulmonary exchange function of individual heart. The greater the oxygen consumption value, the better the individual cardiopulmonary function –21. HIITHigh-intensity intermittent training has been applied in the recovery of various diseases. Meta-analysis by Wewege et al.  comparedThe study by Trachsel et al.  divided Although studies , 14, 17 Patients were divided into 2 subgroups in this study by different disease types: the coronary heart disease group and the heart failure group. However, the heterogeneity was still shown in the 2 groups. Source of heterogeneity comes from multiple factors such as patient age level, disease type, and difference in intervention methods, which could not be further analyzed in depth. Funnel plots of the two-sided distribution indicate that publication bias is less likely. The quality of the studies included in this meta-analysis was high. However, the sample size in the studies was small on average. Therefore, the RCT study needs to be further deeply explored. But this study also has some shortcomings. The studies were divided into 3 levels. There would be a huge variation in level B and a big jump from level B to C based on the description. We will use a more detailed grading of the literature in the next further research. Differences between the two cardiovascular diseases are also mentioned in this study, but this issue has not been investigated further, which may be related to multiple factors, which we will examine separately in the next in-depth study.520 patients in 10 articles were in this meta-analysis. The results of this study show that high-intensity intermittent training is superior to moderate-intensity training in terms of improving cardiorespiratory fitness and quality of life in cardiovascular patients. However, lower case number of literature included in this study is small, so randomized controlled studies still need to be further explored.