Considering hits and misses from past directed domestications of insects and other species, we here provide a workflow to avoid common pitfalls in directed domestication programs.• This workflow underlines that it is crucial to find relevant candidate species for domestication. Candidate species must address human need/demand and meet a set of minimal requirements that shape their domestication potential. The domestication potential can be defined through an integrative assessment of key traits involved in biological functions.• Geographic differentiation of key traits in a candidate species and the maintenance of adaptative potential of farmed populations should also be considered to facilitate domestication and answer to future challenges.Domestication has irrevocably shaped the history, demography, and evolution of humans. It is a complex phenomenon which can be seen as a continuum of relationships between humans and nonhuman organisms, ranging from commensalism or mutualism to low-level management  or, even, direct control by humans over resource supply and reproduction , 2015. TThe complexity of the domestication process is mirrored by the diversity of past domestication histories. For instance, three main patterns of domestication histories can be identified for animal species: the “domestication pathways” . The comBombyx mori, Lepidoptera) and the honeybee  (see domestication histories reviewed in Bombus spp.) is an insect example of domestication triggered by an unmet human demand: the development of fruit production  in greenhouses, which required importing insects such as bees to ensure the pollination ecosystem service. However, previously domesticated species, such as honeybees, are quite inefficient pollinators for such crops whereas bumblebees are ideal pollinators for these plants (Gromphadorhina portentosa), and laboratory organisms , or for sterile insect technique development, and raw material/food production , as well as productions with a low productivity and/or profitability, are often doomed to failure e.g., . TherefoAcipenser sturio) in the wild, 2) to allow reintroduction for wildlife conservation . Such domestications happen 1) when a wild species already exploited by humans becomes rare  are involved in different biological functions  and 2) are not necessarily correlated among each other, implying that expression of a trait cannot be inferred from other traits . This meMaking an integrative assessment of domestication potential should not hide the fact that some key traits can be more important than others. For instance, very low survival rate or low reproduction rate during the assessment will certainly stop ongoing domestication trials because they prevent the completion of the life cycle. Therefore, minimal expression threshold  should be defined, potentially by a panel of stakeholders, for the most important traits relatively to the domestication purpose  but not for another trait . This requires making a consensus between results of key trait assessment to identify the best candidate species for a service-targeted domestication or to objectively assess the relevance of a species-targeted domestication . ScoringBombus terrestris) is one of the few stunning examples where population-specificity inclusion in domestication programs fostered a fruitful economic development. The buff-tailed bumblebee displays significant differentiation in key traits  between differentiated groups of populations corresponding to subspecies  proved to have superior characteristics from a commercial point of view  and became the dominant taxa in the bombiculture industry  through the calculation of a domestication potential score through the help/advice from stakeholders  keepFurther attention should be paid to genetic diversity when constituting the initial stock . If thisDuring domestication, farmed populations undergo new selective pressures from the rearing environment, a relaxation of wild environmental pressures, and other genetic processes, such as founder effect, genetic drift, or inbreeding . These pGallus gallus domesticus, Galliformes, Salmo salar, Salmoniformes, A. mellifera populations to create an Africanized strain which would be better adapted to tropical conditions and present a higher honey production  can impact production systems  and/or availability of important resources for farming . This plInsect farming can face these changes thanks to species intrinsic features such as large climatic tolerance or generalist diet. In the context of global changes, the ability to cope with environmental changes is thus a valuable information that should be considered early in the process, during the assessment of candidate species domestication potential  to improve farmed populations (through trait selection or wild introgression) or create new specialized strains . HoweverFinally, in extreme cases in which farmed stocks cannot face/be adapted to new socioeconomic and environmental contexts, it will be necessary to start new domestication programs using new candidates (new wild species or population groups).Insect farming is expected to expand in the future but remains challenging because of the difficulty to domesticate new species. We proposed a conceptual workflow to avoid major problems commonly encountered during domestication programs. We underlined the importance of 1) considering how new species production could respond to an unmet human demand with a viable and efficient business model and 2) assessing the domestication potential of candidate species through an integrative assessment. We argued that geographic differentiation between wild populations of a candidate species can be valuable. At last, we emphasized the importance of maintaining the adaptive potential of productions to answer to current and future challenges.


Signaling chemicals produced by one organism that bring about a behavioral response in a recipient organism are known as semiochemicals, with pheromones being a well-known example. Semiochemicals have been widely used to monitor and control insect pests in agricultural and forestry settings, but they have not been widely used in weed biological control. Here, we list the few examples of semiochemical use in the practice of classical weed biological control, where a natural enemy (biocontrol agent) from the native range of the plant is introduced into the new invaded range. Uses of semiochemicals include monitoring of biocontrol agents (sex pheromones), keeping biocontrol agents together long enough for them to become well established (aggregation pheromones) and repelling agents from areas where they may be unwanted (host or non-host plant volatile organic deterrents). We make the case that given the vast potential of biological control in suppressing invasive plants it is well worth developing and utilizing semiochemicals to enhance biocontrol programs.In agricultural systems, chemical ecology and the use of semiochemicals have become critical components of integrated pest management. The categories of semiochemicals that have been used include sex pheromones, aggregation pheromones, and plant volatile compounds used as attractants as well as repellents. In contrast, semiochemicals are rarely utilized for management of insects used in weed biological control. Here, we advocate for the benefit of chemical ecology principles in the implementation of weed biocontrol by describing successful utilization of semiochemicals for release, monitoring and manipulation of weed biocontrol agent populations. The potential for more widespread adoption and successful implementation of semiochemicals justifies multidisciplinary collaborations and increased research on how semiochemicals and chemical ecology can enhance weed biocontrol programs. Invasive plant species are a global problem, impacting and threatening the sustainability of agriculture and ecosystems ,2. ClassThe field of chemical ecology has been widely adopted in integrated pest management and numerous pest control programs have succeeded due to the deployment of semiochemicals ,6. HowevOur goals for this report are to describe the few systems where semiochemicals have been used to enhance weed biocontrol see , and to The typical pathway for development of semiochemicals as weed management tools begins with field-based observations, such as the observation of aggregation of conspecifics, long-range mate finding, or attraction to host plants during dispersal. Observations can then lead to hypotheses regarding the role of semiochemicals in modulating herbivore behavior. The next steps occur in specialized laboratory settings where behaviorally active volatile compounds are captured from an air stream passed over living insects or plants (or insects feeding on plants) in settings designed to mimic field conditions., The mix of collected volatile compounds is fractionated using gas chromatography (GC), and antennally active compounds are identified from the fractionated compounds using electroantennagraphy detection (EAD) to produce parallel plots (GC-EAD) , which aThere are a variety of behavioral assays with choice tests being typical for measuring behavioral responses to semiochemicals. Choice tests are often conducted in olfactometers, which measure chemotaxis in an arena where the insect is subjected to air streams with and without the test compound or compounds . The loUlex europaeus L., biological control program in New Zealand where two moth species, the gorse pod moth, Cydia succedana (Denis & Schiffermüller) (Lepidoptera: Torticidae) and the gorse soft shoot moth, Agonopterix umbellana (Fabricius) (Lepidoptera: Depressariidae) were monitored with sex attractants screened from known pheromonal components of congeneric species . The deployment of pheromone-baited traps for detection of D. carinulata also provides an example of how semiochemical baits can be effectively used to detect low-level presence during the initial range expansion of a newly established agent. In the case of Tamarix biocontrol D. carinulata-induced defoliation was readily apparent and detectable using remote sensing  but theg  resulted in increased densities of the agent in targeted Tamarix stands -2-hexenal, newly discovered to be repellent to reproductive D. carinulata, which would be the push [Tamarix to stands outside of flycatcher nesting territories, while deterring defoliation at flycatcher nest sites during breeding season  while luring them toward an attractive source (pull) . It has the push . Strateg season  on diffuse knapweed (Centaurea diffusa Lam.) and the stem boring weevil Mecinus janthiniformis Tosevski & Caldara (Coleoptera: Curculionidae) on Dalmatian toadflax  Mill.) and there are undoubtedly many more examples of aggregation among biocontrol agents. In contrast to the above examples, most weed biocontrol agents have not been investigated for semiochemical involvement in behavior and host plant interactions. Other weed biocontrol agents, particularly adult beetles, are found in aggregations, making it reasonable to hypothesize semiochemical involvement in bringing and keeping them together on the host plant. Discovery and development of semiochemicals in aggregating species would begin with isolation of antennally active compounds and proceed from there and could lead to enhancement of establishment and efficacy in currently uninvestigated agents. We have noted aggregation behavior in the seed head feeding weevil Sex pheromones are another class of semiochemicals that has proven useful in weed biocontrol . The patGalerucella males fail to emit aggregation pheromone when feeding on non-target suboptimal hosts [Carduus nutans L.), Rhinocyllus conicus Frölich, (Coleoptera: Curculionidae) is known to select native thistles in the field. Studies on differences between VOC profiles of the target and native species may lead to development of repellent semiochemicals to diminish attack on native thistles. This possibility was suggested by the authors of that study as a way to use repellent compounds to manage for endangered thistles [Mogulones borraginus F. (Coleoptera: Curculionidae) to volatile components from the target-hound’s tongue  were compared to those from non-target species to help define the host range of this insect [M. borraginus and their responses to semiochemicals in combination with visual cues, the findings revealed semiochemical attractants produced by C. officinale, as well as repellents produced by non-target species. The information and methodologies used in those studies could readily apply to implementation programs using M. borraginis, where attractants and repellents would be very useful. This report has been directed toward the use of chemical ecology in the implementation of a weed biocontrol program, distinguished from the activities associated with safety and host specificity of agents. Information on semiochemical signaling pathways can inform both sets of activities. For instance, the discovery that al hosts  providesal hosts ,63,64,65s insect ,62. WhilDiorhabda aggregation pheromones are not commercially available and so researchers must either synthesize the pheromone or work with chemists to synthesize it prior to initiating experiments [Diorhabda pheromones this was accomplished through a cooperative project with a private company , to incorporate semiochemicals into a commercially available flowable wax-based controlled release matrix known as SPLAT®. The formulation was shown to provide an acceptable release rate for the semiochemicals even after 30 days in the field [Once semiochemicals have been identified in weed biocontrol agents, the last barrier to incorporation into weed management programs is the availability of these compounds to biocontrol practitioners and resource managers. For example, the eriments ,23,50,54he field  for specThese examples are meant to stimulate discussion and research on the use of semiochemicals as tools for biological control practitioners to increase efficacy of weed biocontrol. When implementing a biological control program, the potential benefits of the insect pheromones and other semiochemicals should be considered, as they can be a critical factor in successful establishment, monitoring, and impact of the program. The integration of chemical ecology and weed biocontrol offers fertile research opportunities that can enhance the services provided by biological control programs.


The small patient populations inherent to rare genetic diseases present many challenges to the traditional drug development paradigm. One major challenge is generating sufficient data in early phase studies to inform dose selection for later phase studies and dose optimization for clinical use of the drug. However, optimizing the benefit-risk profile of drugs through appropriate dose selection during drug development is critical for all drugs, including those being developed to treat rare diseases. Recognizing the challenges of conducting dose finding studies in rare disease populations and the importance of dose selection and optimization for successful drug development, we assessed the dose-finding studies and analyses conducted for drugs recently approved for rare genetic diseases.Of the 40 marketing applications for new molecular entity (NME) drugs and biologics approved by the United States Food and Drug Administration for rare genetic diseases from 2015 to 2020, 21 (53%) of the development programs conducted at least one dedicated dose-finding study. In addition, the majority of drug development programs conducted clinical studies in healthy subjects and included population pharmacokinetic and exposure–response analyses; some programs also conducted clinical studies in patient populations other than the disease for which the drug was initially approved. The majority of primary endpoints utilized in dedicated dose-finding studies were biomarkers, and the primary endpoint of the safety and efficacy study matched the primary endpoint used in the dose finding study in 9 of 13 (69%) drug development programs where primary study endpoints were assessed.Our study showed that NME drug development programs for rare genetic diseases utilize multiple data sources for dosing information, including studies in healthy subjects, population pharmacokinetic analyses, and exposure–response analyses. In addition, our results indicate that biomarkers play a key role in dose-finding studies for rare genetic disease drug development programs. Our findings highlight the need to develop study designs and methods to allow adequate dose-finding efforts within rare disease drug development programs that help overcome the challenges presented by low patient prevalence and other factors. Furthermore, the frequent reliance on biomarkers as endpoints for dose-finding studies underscores the importance of biomarker development in rare diseases. The development of therapies for rare diseases poses a myriad of challenges, including difficulties enrolling patients into studies, variability in the course of disease, a lack of well-established study endpoints to support drug approval, the perceived lack of economic incentive for drug developers, and many others. In addition, many rare diseases are genetic, and this presents additional challenges because genetic diseases often have genetic and phenotypic heterogeneity . TherefoThe Orphan Drug Act of 1983 and other incentive programs have been introduced to foster and expedite development of orphan drugs, which are defined as therapies used to treat diseases with less than 200,000 individuals in the United States . IncentiDrug development and approval for rare diseases should balance drug development challenges and medical need against the need to demonstrate that a therapy's benefits outweigh its risks. While regulations indicate it is appropriate for the FDA to exercise flexibility in applying the regulatory standards for drugs to treat serious and life-threatening diseases, the FDA also must preserve appropriate guarantees for safety and effectiveness , 7. OptiDose optimization relies on a thorough understanding of dose-exposure–response relationships. While data from many sources are necessary to adequately characterize dose-exposure–response relationships, understanding a drug’s pharmacokinetic (PK) and pharmacodynamic (PD) effects over a wide range of dosages is essential . These dForty new molecular entities (NMEs) were approved for rare genetic diseases between 2015 and 2020. Seventeen of the approvals (43%) were small molecule drugs, 8 (20%) were oligonucleotide therapeutics, 6 (15%) were monoclonal antibodies, 6 (15%) were enzyme-replacement therapies, and 3 (7%) were for other molecule types. The most common indications were for neurologic diseases , inborn errors of metabolism , and hematologic diseases   conducted at least one dedicated dose finding study  had a study with at least one dose-finding element . Similar to analysis of all drug development programs, the majority of drug development programs that did not conduct a dedicated dose-finding study conducted studies in healthy subjects and included population PK analyses and exposure–response analyses, while a minority included dose-finding studies from other patient populations Table . OverallThirteen of the dedicated dose-finding studies identified a clinical outcome or PD biomarker as the primary endpoint. The vast majority of primary endpoints utilized in dedicated dose-finding studies were biomarkers, while clinical outcomes or a combination of biomarkers with clinical outcomes or COAs were also used Table . When coTwenty-two of the dedicated dose-finding trials listed an efficacy measure as a secondary endpoint. Similar to the analysis of primary endpoints, biomarkers were the most commonly used secondary endpoints, while clinical outcomes and COAs were used more rarely Table . When coDose-finding studies are a critical component of drug development and failure to identify a safe and effective dose can cause clinical trial failures, and is frequently cited as a reason for non-approval of drugs . Rare geIn drug development, dose selection for confirmatory efficacy studies is often based on dose-finding studies that assess a wide range of dosages in the relevant patient population and generate robust data on dose-exposure–response relationships. These data are then used to identify the dosing regimen or regimens that are most likely to demonstrate safety and efficacy in later studies, and thus most likely to meet the regulatory standards for marketing authorization. Our study showed that just over half of NME drug development programs for rare genetic diseases conducted a dedicated dose-finding study. Given the challenges associated with conducting clinical studies in rare disease populations, alternative methods to generating dose-exposure–response data to inform dose selection may be appropriate, such as titrating the dose within a study or evaluating multiple dosage regimens in late phase safety and efficacy study. After accounting for all of these methods, a significant number of drug development programs remained (18%) that did not conduct any dose-finding studies. These findings may indicate that alternative strategies are being used to generate data to inform dose selection and optimization for drugs used to treat rare genetic diseases or may suggest that dose finding is not emphasized or prioritized in these programs, which could potentially lead to non-approval of an effective drug that was improperly dosed or approval of a drug at a dosage that does not have an optimal benefit-risk profile. However, one limitation of our analysis is that we did not compare drug development programs that ultimately resulted in an approved product to those that did not; as such, we cannot make a direct conclusion about the impact of conducting these studies on approval or the approved dosing regimens.We found that the dose-finding studies conducted within NME drug development programs for rare genetic diseases usually included at least 3 and often 4 or more dosage regimens, and the majority included dosage regimens that spanned at least a 5-fold range and often greater than a 10-fold range. The use of several dosages and a wide range of dosages is critical to establishing dose–exposure–response relationships to adequately inform dose selection and optimization , as wellOur analysis focused on dose-findings studies as a principal data source for dose selection and optimization. However, other methods may also provide valuable data regarding dose–exposure–response relationships that can inform dose and optimization; therefore, we also assessed the frequency that data from healthy subject studies, other patient populations, and data from population PK and exposure–response analyses were submitted in support of the application. We found that the majority of NME drug development programs conducted clinical studies in healthy subjects and included population PK analyses and exposure–response analyses, while only a few programs also included dose-finding data from other patient populations in their submissions. The use of these alternative data sources did not appear more common in programs that did not conduct a dedicated dose-finding study, so we cannot conclude that these methods are relied upon when dedicated studies are not feasible; however, they do appear to be used frequently to provide information within rare genetic disease drug development programs. These, and other innovative methods of characterizing dose–exposure–response information, such as microdosing studies, model-informed drug development approaches or complex innovative trial designs, that rely on quantitative models derived from preclinical and clinical data sources, can be used to provide valuable information on dose selection and optimization and help increase the probability of regulatory success in the absence of dedicated dose-finding trials –19.Biomarkers are used for many purposes in drug development, particularly as measures of drug response in dose-finding studies. We found that biomarkers were by far the most commonly used primary and secondary endpoints for dedicated dose-finding studies, and the same biomarkers were frequently the primary endpoint in the confirmatory efficacy trial. The use of biomarkers for endpoints in dose finding studies is reasonable, and may be preferred over clinical outcomes because biomarkers are often more sensitive to drug effects and more directly related to drug plasma concentrations compared to measuring clinical outcomes, which can be impacted by multiple factors . In addiBiomarkers may be able to help address some of the major challenges in rare disease drug development, such as practical dose-finding studies that inform dose selection and optimization, generating confirmatory evidence of effectiveness , and ultimately as surrogate endpoints for approval in lieu of measuring clinical outcomes. However, efforts are needed to appropriately develop and validate biomarkers for these purposes. To accomplish this, a stepwise approach could be used where a thorough understanding of the mechanistic role of the biomarker in the disease, coupled with data that correlates the biomarker to clinical outcomes, could initially support use of the biomarker as an endpoint for dose-finding studies before data are generated to support the use of the biomarker as a validated surrogate endpoint in efficacy trials. Although this approach involves some risk because of the uncertainty of the biomarker’s ability to predict the clinical outcome prior to being validated as a surrogate endpoint, this may be an acceptable trade-off to allow informative dose finding studies that are more practical to conduct.Our study showed that NME drug development programs for rare genetic diseases utilize several different data sources for information on dosing. However, a significant number of drug development programs did not have any clinical studies classified as a dose-finding study. In addition, we showed that biomarkers play a key role in dose-finding studies for rare genetic disease drug development programs. Our findings highlight the need to develop study designs and methods to allow adequate dose-finding efforts within rare disease drug development programs that help overcome the challenges presented by low patient prevalence, variable course of disease, and other factors. Furthermore, the frequent reliance on biomarkers as endpoints for dose-finding studies underscores the importance of biomarker development in rare diseases.Rare genetic diseases were defined as diseases caused by germline genetic alterations and meeting the U.S. criteria for a rare disease  . To idenDedicated dose-finding studies were defined as phase 1 or 2 clinical studies in the disease population for which the drug was initially approved that studied more than one dosing regimen in parallel and included an efficacy measure as a primary or secondary objective or endpoint. Studies were not counted as dedicated dose-finding studies if only a single dose was administered , the study was an extension of a previous study, or the study was the phase 3 confirmatory efficacy study for the drug.All clinical studies conducted as part of individual drug development programs were identified from the Table of Clinical Studies submitted with the application. In addition to dedicated dose-finding studies, study information was collected from clinical studies that utilized titration and confirmatory clinical trials that included more than one dosing arm because these studies contain some features of dose-finding studies  and data from these studies can also be used to inform dose selection and optimization; the combination of dedicated dose-finding studies and additional studies that incorporate these features are referred to as “all dose-finding studies” within this manuscript. For each dose-finding study, the number of dosage regimens and range of doses evaluated were captured from the study report.We also determined whether sponsors used additional methods (other than dose-finding studies) to inform dose selection and optimization, such as conducting pharmacokinetic studies in healthy subjects or in other patient populations. Healthy subject studies were defined as studies in which multiple dosing arms were studied in healthy subjects. Dose-finding trials in other patient populations were defined as phase 1 or 2 clinical studies that studied multiple dosing arms where an efficacy measure was a primary or secondary objective in patients with a disease other than the one indicated in the initial approval. In addition, we assessed whether sponsors conducted dose-finding analyses other than clinical studies, including exposure–response or population PK analyses, by searching the clinical pharmacology review, which was obtained from Drugs@FDA . We furtThe primary and secondary endpoints used in dedicated dose-finding studies were collected from the clinical study reports. Endpoints were then categorized as biomarkers, clinical outcomes, or clinical outcome assessments (COAs). Endpoints for confirmatory safety and efficacy trials, defined as the confirmatory efficacy trials cited in the Clinical Studies section (Section 14) of the FDA-approved product labeling , were identified and cross-checked with the clinical study report submitted by the applicant. To evaluate the continuity of clinical trial endpoints across studies conducted during drug development, we determined if a primary or secondary endpoint for the dedicated dose-finding study was also used as the primary endpoint for the confirmatory efficacy trial(s). To be considered “matched,” the endpoints being compared needed to study the same variable , but could differ in measurement or analysis aspects . For example, if a drug program had a dose-finding study using percent change in bodyweight from baseline as a secondary endpoint and one of the confirmatory trials studied absolute change in bodyweight from baseline as the primary endpoint, these would be considered “matching” endpoints. If a drug development program used composite or co-primary endpoint(s), the endpoints would be considered “matched” if any single endpoint that made up the composite or co-primary endpoint in the confirmatory trial was the same as an endpoint studied in the dose-finding trial.


Excessive precipitation events have greatly increased in several grape growing regions due to human-caused climate change. These heavy downpours result in a myriad of problems in the vineyard including soil aggregate breakdown, soil runoff, nutrient leaching, excessive vine vegetative growth, and diseased fruit. The negative impacts of excessive precipitation events on vineyards are exacerbated by the maintenance of bare soil under the vines. Exposure of bare soil results in soil erosion and runoff which pollutes nearby watersheds; raindrops weaken and break apart soil aggregates, leading to increased soil erosivity and contributing to the formation of surface crusts. In addition to excessive precipitation events, some grape growing regions can be characterized by fertile soils. The availability of ample water and nutrients can lead to highly vigorous vines with shoot growth continuing through harvest. Long shoots and large leaves result in shaded fruit, a humid vine microclimate, and excessive cluster rot. In this review, we examined how either natural  or seeded under-vine vegetation (UVV) can help mitigate many of the problems associated with excessive precipitation. Through providing vegetative coverage to reduce the force of raindrops, increasing soil organic matter and enhancing soil microbial diversity, UVV can reduce the soil degradation and off-site impacts caused by excessive precipitation events. Through competition for soil resources, UVV can reduce excessive vegetative growth of vines and decrease cluster rot incidence and severity, although grapevine response to UVV can be highly variable. We discussed recent advances in understanding below and aboveground vine response and acclimation to UVV and presented current evidence of factors influencing the impact of UVV on vine growth and productivity to assist practitioners in making informed decisions and maximize the ecosystem services provided by UVV. There has been increased interest in understanding grapevine response and acclimation to changes in water availability induced by climate changes in order to adapt management strategies. Although increased drought is a major agricultural challenge and considerable emphasis has been placed to ameliorate the impact of lower water availability on wine grape production worldwide, some grape growing regions are facing challenges relating to more erratic rainfall patterns and excess water availability. In general, heavy precipitation events  are becoming more intense and more frequent across most of the United States . This inThese heavy precipitation events can lead to a multitude of detrimental impacts on plants and soil in vineyards, particularly those with a lack of soil cover, as well as their neighboring ecosystems. Exposure of bare soil results in greater impact from raindrops, which weaken and break soil aggregates apart, increasing the erosivity of soils and contributing to the formation of crusting on the soil surface . In vineGrapevines themselves can also be detrimentally impacted by increased and/or excessive precipitation. An increase in plant available water – and hence nutrient availability – can lead to greater vegetative growth  and berrIn grape growing regions with high precipitation, where inter-row vegetation is already maintained, researchers have been experimenting with under-vine vegetation (UVV) to alleviate some of the detrimental effects to soil and plants caused by ample precipitation and provide further benefits to the vineyard ecosystem. Both annual and perennial cover crop species have been intentionally planted in the area beneath the vines, but adoption of natural vegetation  has also been explored. In addition to the eastern United States, UVV has been trialed in a range of climates including wine regions in France , Spain , AustralThis review details how UVV can help ameliorate climate challenges related to increased heavy precipitation; we focus on key soil and plant traits that could be impacted by implementing UVV, describe the current understanding of the complex UVV-vine interactions, and identify knowledge gaps in the published literature. Our discussions are intended to provide a framework that can guide future research and increase UVV adoption. Due to the common use of inter-row cover crops in many wine regions with high precipitation, we focus on the additional impact UVV provides in vineyards where inter-row vegetation is already maintained.Protecting soil from degradation is important for the long-term sustainability of a vineyard. Introducing cover crops into what was traditionally considered a perennial monoculture system can help achieve this goal . Cover cSoil organic matter (SOM), soil organic carbon , and total carbon (C) can markedly increase or decrease as a function of soil management, although the response to management can take many years to become detectable. Repeated herbicide applications and cultivation result in bare soil, negatively impacting SOM and SOC . Plants Festuca rubra) was planted in a young vineyard  3 years after UVV  as an UVV for 4 years resulted in 36% greater aggregate stability than under-vine soils maintained with the herbicide glyphosate and 23% greater than those maintained with cultivation. Soils from the under-vine white clover plots maintained almost 75% of aggregate mass after a simulated rain event , chicory (Cichorium intybus), tillage radish (Raphanus sativus), and alfalfa (Medicago sativa), had soil respiration rates up to 75% greater than plots maintained with glyphosate  was recorded when grapes were harvested from plots managed with UVV rather than bare soil  and herbaceous (cover crop) species compared to using inter-row cover crops only, which could result in a greater resource uptake limitation and aboveground effects. When cover crops or natural vegetation grow in the inter-row only, the grapevine root system mainly colonizes the under-row area while the cover crops the inter-row, suggesting a compartmentalization of space and resources . In drie3 soil) can be up 10 times that of young grapevines  could decrease vine access to specific soil resources  which are not homogeneously distributed across the soil profile . The entThe seasonal dynamics of root growth can affect the temporal interaction between the UVV and grapevines. Although belowground grapevine phenology is less predictable and not strictly coupled to aboveground phenological phases , vine roCover crops with different growth cycles  might introduce competition at different times of the vine growth cycle. Cool-season grasses exhibit a growth pattern that parallels the fast spring vegetative growth of vines and can be more effective in suppressing primary shoot growth compared to summer annual cover crop species which are planted later in the season. Competition for resources during early stages of berry development may, however, decrease berry size and thus yield potential. If summer annual UVV competes later in the season with the grapevines they could decrease the duration of lateral shoot growth  or, in oLolium multiflorum) and buckwheat (Fagopyrum esculentum), had longer median life span than those in the under-vine bare soil plots  vines grafted either on 101-14 Mgt (V. riparia × V. rupestris) or Riparia (Riparia gloire) were exposed to UVV (red fescue) for 1 year, they were able to compensate for reduction of absorptive RLD in the shallow soil (0–20 cm) with greater root length in deeper soil (21–40 cm), which was described as a zone of lower competition compared to the 0–20 cm depth increment (Vitis vinifera) vines grafted on the same rootstock (101-14 Mgt) of Other studies explored UVV-induced responses of absorptive root traits which are typically associated with increased efficiency of nutrient uptake, such as production of absorptive roots with smaller diameter, greater root length to mass ratio , and greater branching intensity . Effectsncrement . The samvia reduced water availability which can decrease nutrient movement toward the roots by mass flow or diffusion  are the most sensitive and first affected by water deficits and nutrient deficiencies. Reduction in nutrients in vineyards with UVV could be direct, through lower soil availability, or indirect, iffusion  and N miiffusion .Most work from regions with ample precipitation noted no or minimal competition for water in vineyards with UVV . Only a In regions where water availability is not typically a limiting factor, competition for nutrients might be more relevant. Compared to vines maintained with under-vine herbicide, UVV decreased plant N status  and extr2 concentration of vines were unaffected by treatment. More research is needed in this area.It still unclear if decreased soil resource uptake induced by UVV competition has a meaningful impact the capability of a vine to assimilate C and on the allocation ratios among C sinks . Interaction between a woody and herbaceous species is a dynamic process and acclimation strategies, although still understudied, might evolve over the years. Long-term studies (>5 years) of UVV in vineyards are needed to assess the sustainability of this practice across the lifetime of the vineyard. To date, we are aware of only two studies conducted in the humid eastern United States that assess aboveground vine response to UVV over 7 years . In the In addition to investigating shifts in root growth and morphological traits in response to UVV, as described earlier, several studies explored grapevine root association with beneficial microbes as a vine acclimation strategy to UVV. To date, investigations were mainly focused on arbuscular mycorrhizal fungi (AMF); however, other root-associated microbes that impact vine functioning might be affected by UVV as well. The guiding hypothesis was that vines growing with UVV would have greater AMF colonization than those growing with bare soil under-vine to improve efficiency of nutrient absorption especially in deeper soil layers not colonized by UVV roots. This could provide the vines with enough resources to maintain growth in competitive soil environments. However, to date, there is no indication that vines increase AMF colonization in response to UVV across the soil profile (0–100 cm) of young and mature vineyards .Grapevine interaction with UVV over time can also be influenced by the root system genotype, but strong evidence is still lacking. Rootstocks are usually classified from low- to high-vigor based on their influence on the scion vegetative growth. If high-vigor rootstocks have greater RLD and higher soil water and nutrient depletion than low-vigor rootstocks they could more readily acclimate to belowground UVV competition. They might also be able to explore deep soil layers faster (both as a proportion of the whole root system and as absolute RLD) and therefore use more water in deeper soil too. These root traits could lead to a different aboveground response to UVV, such as less relative growth reduction for a grapevine grafted on a high-vigor compared to low-vigor rootstock. We could also speculate that, while differences between rootstocks might be exacerbated by competition with UVV, they would also diminish over time if the vines are able to acclimate to competition.Riparia; Riparia Gloire) or moderate (101-14 Mgt) vigor, 1 year after UVV establishment and 2 years later (3 of soil) between 0 and 20 cm, at deeper depths only the medium-vigor root system was influenced by the presence of UVV. These results suggest that root system genotypes might differ in their response to UVV competition, but that it might take a few years to observe significant differences. However, it is still unclear if differences in belowground rootstock-UVV interaction will lead to significant changes in aboveground growth.Two studies conducted at the same site examined below and aboveground responses to UVV competition of young grapevines (Noiret) grafted on two rootstocks that are considered to impart low  and the practitioner’s production goals. The balance between ecosystem services and disservices provided by UVV is dynamic and there are a large number of factors that will influence vine response to UVV. Practitioners should carefully consider these factors if deciding to adopt UVV . While fStudies on implementation of UVV in environments with high precipitation have investigated both perennial and annual species. In colder climates, annual species were selected since soil is generally hilled above the graft union for winter protection of scion buds on the trunk. Annual species are then replanted after the hill is pulled down in the spring. As a function of the hilling/unhilling, UVV in these vineyards will potentially compete with the vine for a shorter period of time compared to perennial UVV.Choice of species will determine the competitiveness of the UVV within the context of the site and season. Species range not only in their competitiveness for water and nutrients, but also in the timing of when they are most competitive. For example, natural vegetation  will generally provide almost season-long competition as a function of the diversity in species in the stand  althoughLegumes can release N depending on management, which can be an ecosystem service or disservice depending on production goals . ReleasePlanting of UVV can be accomplished by hand or mechanically . Mowing As UVV can compete with vines, water and nutrient status must be carefully monitored through the season to ensure vines have the required resources . The impBoth vineyard and environmental factors will impact the competitiveness of the UVV with the vine as well as the ability of the vine to adapt to the competitive environment. These factors include vine vigor, vine age, soil properties, and soil nutrient and water availability.Vigorous vines can withstand greater competition from UVV as vegetative growth of the vine tends to be reduced prior to reproductive growth . PresumaThe physical, chemical, and biological characteristics of the soil will mediate competition for water and nutrients between the vine and the UVV. Soils lower in SOM will provide fewer nutrients and water holding capacity will be reduced compared to high SOM soils, potentially resulting in greater competition between the vine and UVV. Soil depth will impact the ability of the vine root systems to explore a greater soil volume in response to UVV competition, impacting vine nutrient and water status . In vineBoth water and nutrient management plans may need to be adjusted with the adoption of UVV although interventions and timings of those interventions will be dependent on soil and environmental conditions. Pre-bloom irrigation may be necessary with the adoption of UVV in drier climates . In climThe impact of UVV on fruit composition and wine sensory perception would likely be indirect, with flavor and aroma compounds potentially impacted by plant adaptation to UVV through changes in berry size, leaf area to fruit ratio, fruiting zone microclimate (light exposure and temperature), and soil resource availability. The ability to study the impact of UVV on wine sensory characteristics has been hampered by the use of laboratory-style winemaking practices  as opposed to commercial fermentations. Nonetheless, a handful of studies have investigated the impact of UVV on consumers’ ability to differentiate resulting wines but the results are inconsistent among years and studies .Adopting and maintaining UVV includes the following potential costs: site preparation, seed, planting, mowing, and additional irrigation and fertilization. However, savings for producers may be realized through elimination of herbicide application and/or cultivation as well as reduced need for canopy management . Labor costs of establishment and maintenance of under-vine bare soil compared to UVV are difficult to gage as it depends on the cover crop species  used and its management needs, such as number of herbicide applications, cultivations, or mowing practices. Specific information on the cost of adoption and maintenance of UVV is sparse. Reduction in vegetative growth induced by UVV might require less labor-intensive canopy management practices, such as leaf removal and hedging. Labor savings can be hard to quantify, but a study conducted on Cabernet Sauvignon in a humid climate indicated that vines growing with a perennial fescue as UVV had smaller canopies, which were hedged in about half of the time compared to vines maintained with under-vine herbicide which were more vigorous . SimilarA partial budget analysis could be used to estimate the financial implications of using UVV over more traditional under-vine management practices . For exaAdapting management strategies in the face of climate change are critical for maintaining and improving wine grape production worldwide. Several studies have demonstrated the potential of UVV to preserve soil health in grape growing regions with fertile soil and increasingly excessive precipitation, while also reducing herbicide input and excessive vine growth. This review discussed progress in several research areas which could help explain effects on vine growth and production and vineyard ecosystems . Many UVTo promote widespread adoption of UVV in this changing climate, practitioners need guidelines on under-vine management options that best serve their production goals while maximizing the number of ecosystem services provided. Numerous knowledge gaps still exist which might prevent practitioners from more clearly predicting vine response and acclimation to UVV over the years. JV and MC developed the concept and wrote the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Pseudomonas aeruginosa (Pa) is ubiquitous in the environment and causes opportunistic infections in humans. Pa is increasingly becoming one of the most difficult to treat microorganisms due to its intrinsic and acquired resistance to multiple antibiotics. The World Health Organization estimates that at least 700,000 people die each year from drug resistant microbial infections and have listed Pa as one of three bacterial species for which there is the most critical need for the development of novel therapeutics. Pa is a common cause of bloodstream infections (BSI) and bacterial sepsis. With nearly 49 million sepsis cases and 11 million deaths worldwide, an effective vaccine against Pa could prevent the morbidity and mortality resulting from Pa BSI and lessen our dependence on antibiotics. We reviewed the current landscape of Pa vaccines in pre-clinical and clinical stages over the last two decades. It is readily apparent that Pa vaccine development efforts have been largely directed at the prevention of pulmonary infections, likely due to Pa’s devastating impact on individuals with cystic fibrosis. However, the increase in nosocomial infections, BSI-related sepsis, and the emergence of widespread antibiotic resistance have converged as a major threat to global public health. In this perspective, we draw attention to potential Pa vaccine candidates and encourage a renewed effort for prophylactic vaccine development to prevent drug-resistant Pa BSI.The bacterium  Antimicrobial resistance (AMR) is a major global public health emergency and threatens to render once safe and remarkably efficacious antimicrobial therapeutics, mainly antibiotics, ineffective. AMR has been recognized as a threat to human health by numerous governmental agencies, independent scientists, and international entities, including but not limited to, the World Health Organization (WHO), the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC) and the United Nations UN; . The disPseudomonas aeruginosa (Pa) is one of three highest priority “Critical” bacterial species on the WHO list.AMR is classified by the intensity or degree of microbial resistance to one or more antibiotics. For example, bacteria may exhibit multidrug resistance (MDR), extensive drug resistance (XDR), or even pan drug resistance (PDR) phenotypes. MDR typically refers to bacteria that are resistant to at least one antibiotic in three or more antibiotic classes. XDR means bacteria are susceptible to only one or two antibiotic classes, whereas PDR indicates that bacteria are not susceptible to any known antibiotic class . The WHOPa is a ubiquitous gram-negative bacterial species known for its versatility and propensity to adapt to a wide range of environments. Pa can colonize moist surfaces including medical devices, hospital sinks and drains, respiratory equipment, and disinfectant solutions . Pa requA bloodstream infection (BSI) is defined by the presence of a viable microorganism in the bloodstream that elicits an inflammatory response. In the absence of a protective host immune response or appropriate medical treatment, a BSI can ultimately lead to sepsis. Sepsis is the result of widespread inflammation throughout the body and may result in severe organ dysfunction and death. The global burden of sepsis is challenging to quantify; however, in 2017, the WHO estimated that 48.9 million cases and 11 million sepsis-related deaths occurred worldwide, which accounted for approximately 20% of all global deaths . HealthcWith BSI, antibiotic resistance is a major factor in determining clinical unresponsiveness to treatment and progression to severe sepsis and septic shock. Studies document that Pa is one of the most resistant GNB found in clinical settings , and Pa Rapid empirical administration of antibiotics has long been a cornerstone of sepsis management . HoweverStreptococcus pneumoniae resulted in a 59% reduction in multidrug-resistant strains between 1999 and 2004  have garnered attention as vaccines and adjuvants . OMVs caImmunization with Pa double layered OMVs (DMVs) significantly increased the production of IL-1β, IL-6, IL-2, and IL-12p70 cytokines, promoted maturation of CD11c + dendritic cells, and increased serum IgG titers . VaccinaPa secreted toxins play an important role in infection and may be promising vaccine targets. Exotoxin A (ExoA) is one of the most toxic virulence factors of Pa  and is cTargeting proteins in bacterial iron-acquisition systems also represents a promising vaccination strategy . ImmunizAlginate capsule antigen (Alg) of Pa is a virulence factor that binds to host cells, facilitates biofilm formation, and aids Pa in antibiotic resistance and host immune evasion. Immunization of mice with Alg conjugated to solid lipid nanoparticles (SLN) elicited significant increases in IgG, IgA, and IgM and promoted higher opsonophagocytic killing activity as compared to control-immunized mice . Alg-immSalmonella vaccine displaying PcrV antigen elicited significantly increased levels of antigen-specific IgG at day 21 post vaccination (PaV antigen (PcrV) is the tip protein of the type III secretion system. These secretion systems are present in many GNB and play critical roles in pathogenesis. Several studies have shown that immunization with recombinant PcrV provides protection against Pa in murine models . Immunizcination . Vaccinacination . Immunizcination . A repeacination . Immunizcination . Immunoccination .Pa type IV pili play an important role in early bacterial attachment and have been examined as a vaccine target . VaccinaAs the global population endures the SARS CoV-2 pandemic, health care facilities have been overwhelmed as they continue to care for growing numbers of patients. In the face of medical supply shortages, health care worker exhaustion, and an excess of critically ill patients, comprehensive infection control protocols have been negatively impacted during the pandemic . As a reIt is now appreciated that AMR, and AMR Pa infections, in particular are a growing global public health threat. Past reliance on antibiotics to cure bacterial infections may have limited the pursuit of vaccines to prevent BSI or sepsis caused by Pa. Our systematic review identified 159 Pa vaccine studies over the past 20 years with only 11 that evaluated protection against Pa BSI using intraperitoneal or intravenous challenge models. Indeed, the focus of Pa vaccine development has overwhelmingly concentrated on preventing or eradicating pulmonary infections, such as those that occur in individuals with cystic fibrosis. While development of a vaccine to prevent localized Pa lung infections will also be highly valuable, it will likely be more challenging to develop since vaccine-mediated protection must often target the respiratory tract when it is the site of pathogen entry . Recent We propose that the development of a vaccine to prevent Pa BSI or pneumonia resulting from an invasive infection may be more straightforward, especially if individuals are vaccinated prior to the onset of infection. The pre-clinical studies highlighted here suggest that vaccine-induced opsonophagocytic antibodies could rapidly clear any bacteria once they enter the bloodstream, preventing further dissemination and progression to sepsis or pneumonia. In this scenario, immune responses directed against Pa surface proteins, such as outer membrane proteins that are highly conserved among clinical isolates and upregulated by Pa during BSI, may be ideal. Such vaccine elicited responses could potentially overcome immunodominant or “cloaking” antibodies directed against the Pa O-antigen of lipopolysaccharide which are serotype-specific and attenuate protective responses .The studies reviewed here were limited to mouse models and further investigation in other animal models and eventual human trials will be essential. Failure of past Pa vaccines may be due to a number of factors including lack of relevant animal models, use of inappropriate antigens or adjuvants, and a lack of understanding of protective immunity against Pa. However there has been significant progress in recent years in addressing these challenges . It is aIn summary, the increase in nosocomial infections, the complex sepsis-related empirical antibiotic treatments, and the global rise in AMR dictates that a universal Pa vaccine may be paramount in the near future. Most vaccines take an average of 10 years to advance from discovery to clinical licensure. If AMR projections are accurate, we cannot afford to wait.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.RH performed the literature review and drafted the manuscript. LM revised the manuscript and provided supervision. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


In this Commentary, we will discuss some of the current trends and challenges in modeling microbiome metabolism. A focus will be the state of the art in the integration of metabolic networks, ecological and evolutionary principles, and spatiotemporal considerations, followed by envisioning integrated frameworks incorporating different principles and data to generate predictive models in the future. The past 2 decades have seen significant increases in the technical ability of metabolic models to more accurately represent the underlying metabolic dynamics in biological systems. What started as models of simple organisms, representing only a subset of their genes , has nowA hallmark approach in metabolic modeling is genome-scale metabolic modeling (GEM). The goal of a GEM is to depict the metabolic structure of a cell using the genome sequence as a blueprint, allowing for a complete mapping of reactions in a cell. On top of this blueprint is layered the known metabolic reactions, gene data, and biochemical data to generate a curated reaction network . Within The GEM approach described above has shown significant success in human systems  or a dynamically more accurate community model (microbiome as multiple-assembled organism genomes). A second important consideration is whether static versus dynamic simulations will be used (discussed below) . A thirdSingle-level approaches optimize across the entire community . Evolutionary biologists could be critical of this approach because it bypasses selection at the individual level. Indeed, FBA omits certain stable interactions within communities and can be prone to unrealistic altruistic predictions . CommuniIn contrast, multilevel approaches try to find solutions in which each individual member of a community maximizes its fitness function. This approach is closer to the accepted theory of natural selection/adaptation but elevates the computational demand. OptCom was the first bilevel optimization paradigm to consider both individual and community fitness . BuildinEscherichia coli pairs, because each can act only upon metabolites present in their environments  juxtaposes the steady-state assumptions of FBA . dFBA moronments . That isThis dFBA deficiency is partially addressed by a recent algorithm based also on NE by Zomorrodi and Segrè  in whichdFBA has achieved success in ground truthing models to experimental data and allowed for introducing spatiotemporal dynamics to microbial ecosystems. This is possible through the addition of differential equations for spatial dynamics and/or compartmentalization based on spatial structures to produce a realistic picture. We were able to capture the observed differential relative abundance profiles of microbiota radially, from the intestinal lumen to the mucosal layer, and longitudinally, along the intestinal tract, by proposing a dynamic model of the mucosal cell layer shedding into the lumen directing flow into the succeeding intestinal section and combining SteadyCom and dFBA . ExpliciClostridia causing observed gut microbial metabolomic change after drug treatment  principles in a systematic modeling framework with parameters learned through rigorous model inference techniques will connect theory and data to enhance the usefulness of GEMs for studying complex microbiomes. This process of integration includes gathering heterogenous data sets where myriad supervised and unsupervised methods can be used to concatenate, transform, or model to create algorithm-based models . For exaWithin the set of experimental techniques to generate these data sets, there are two flavors: bottom-up versus top-down. As an alternative to the more commonly used bottom-up synthetic community approach, top-down approaches to study smaller communities of a complex microbiome are emerging. A recent study deconstructed the soil microbiome into functional modules through targeted enrichment of desired metabolic traits. It allows for investigating a community with significantly less complexity and drawing mechanistic conclusions . Another


Diabetic peripheral neuropathy (DPN) is associated with peripheral sensory and motor nerve damage that affects up to half of diabetes patients and is an independent risk factor for falls. Clinical implications of DPN-related falls include injury, psychological distress and physical activity curtailment. This review describes how the sensory and motor deficits associated with DPN underpin biomechanical alterations to the pattern of walking (gait), which contribute to balance impairments underpinning falls. Changes to gait with diabetes occur even before the onset of measurable DPN, but changes become much more marked with DPN. Gait impairments with diabetes and DPN include alterations to walking speed, step length, step width and joint ranges of motion. These alterations also impact the rotational forces around joints known as joint moments, which are reduced as part of a natural strategy to lower the muscular demands of gait to compensate for lower strength capacities due to diabetes and DPN. Muscle weakness and atrophy are most striking in patients with DPN, but also present in non-neuropathic diabetes patients, affecting not only distal muscles of the foot and ankle, but also proximal thigh muscles. Insensate feet with DPN cause a delayed neuromuscular response immediately following foot–ground contact during gait and this is a major factor contributing to increased falls risk. Pronounced balance impairments measured in the gait laboratory are only seen in DPN patients and not non-neuropathic diabetes patients. Self-perception of unsteadiness matches gait laboratory measures and can distinguish between patients with and without DPN. Diabetic foot ulcers and their associated risk factors including insensate feet with DPN and offloading devices further increase falls risk. Falls prevention strategies based on sensory and motor mechanisms should target those most at risk of falls with DPN, with further research needed to optimise interventions.  Diabetes and its long-term complications are considered a global public health emergency linked to high levels of morbidity, disability and mortality. Recently, the International Diabetes Federation estimated that half a billion people suffer from diabetes, which corresponds to 5.3% of the global population . DiabetiDiabetes is associated with multiple complications and perhaps because of the number of potential complications, falls in patients with diabetes is a clinical issue that is only now beginning to gain broader recognition. Falls in the general ageing population is an internationally recognised clinical problem, with one in three people over 65 years falling each year . Falls iDPN-related unsteadiness is common, with a large-scale UK-USA study showing that 23% of the 484 patients with DPN perceived themselves as being unsteady, with associated balance problems . One of This review explores the sensory and motor mechanisms associated with DPN underpinning altered gait biomechanics, which cause balance impairments and increase falls risk in patients with DPN. The schematic diagram presented in Peripheral sensory loss in the feet and motor system deterioration are consequences of DPN and important risk factors for altered gait biomechanics, balance impairment and increased falls risk. Although other risk factors including cognitive function, centrally-acting medications and psychological factors will also undoubtedly play a role in increasing falls risk in the diabetes population, this review primarily focusses on sensory and motor deficits as key falls risk factors, reflecting the proportion of available evidence in this area.probability of having DPN, rather than a certainty. The modified neuropathy disability score (NDS) tests a range of different sensory modalities at the foot and ankle—(i) vibration perception (with a 128 Hz tuning fork), (ii) temperature perception (warm/ cold), (iii) pain (sharp/ blunt) and (iv) the Achilles tendon reflex [Sensory loss in the feet causes alterations to gait biomechanics, affecting balance, and this is a major falls risk factor ,19. Accun reflex —providinn reflex . Other tn reflex ,25 that Diabetes is responsible for a deterioration of muscle strength, which becomes more severe with the development of DPN  and is rMuscle morphological abnormalities are a further typical feature of diabetes and DPN. These alterations include loss of muscle mass and an accumulation of intra and intermuscular fat ,32,34,35Although the decrease in muscle strength may be ascribed to lower muscle mass, it is important to note that diabetes and DPN patients are characterised by poor muscle quality  ,35. Non-Alterations to the natural walking strategy including a slower walking speed, reduced joint range of movement and lower joint moments have been shown to occur even before the onset of measurable DPN ,48,49,50Step length is the anterior–posterior distance between left and right consecutive foot placements, with stride length being the distance between the floor contact points of the same foot within a single gait cycle . PatientStep width is the medio-lateral distance between feet during walking . PatientDiabetes and DPN alters the range of motion across all lower limb joints during walking compared to controls . PatientDiabetes patients have reduced lower-limb muscular strength (between 8% and 45% weaker) compared to age-matched non-diabetic controls ,32,33,41Although lower joint moments in diabetes patients could be explained by a slower walking speed, a recent study highlighted that non-neuropathic diabetes patients and particularly those with DPN were able to reduce ankle joint moments compared to controls even while walking at the same speed . In this‘Operating strength’ can be quantified by relating the joint moments generated during gait to an individual person’s maximum strength capability for that same muscle group (tested under the same conditions between the gait task and maximum muscle testing). This provides an indication of how close people are operating relative to their maximum muscular capabilities during gait  patients with severe DPN, (ii) non-neuropathic diabetes patients and (iii) aged-matched controls without diabetes—consistently show a graded response in terms of the extent of alteration to gait parameters, with gait parameters most severely affected in patients with DPN, followed by non-neuropathic diabetes patients and matched controls as the reference group. Gait alterations in non-neuropathic diabetes patients have also been reported in other gait-related variables including impaired visual gaze behaviour during gait , reducedGait variability, the variation in movements from step to step, is a common assessment of gait ‘quality’, since greater variability can be indicative of diminished muscular and neurological control and associated with increased falls risk in the diabetes population . VariabiDPN has been shown as a strong independent predictor of falls risk ,9,10,11,Self-perceived unsteadiness measured using two specific items on the neuropathy- and foot ulcer-specific quality of life instrument (NeuroQoL), has been shown to discriminate between patients with DPN from non-diabetic controls and notably, from non-neuropathic diabetes patients . This isOne of the major reasons why DPN has been shown to be an independent risk factor for falls is due the complete absence of peripheral foot sensation and the delayed neuromuscular control this causes during gait . InsensaAlthough often difficult to untangle the effects of sensory and motor neuropathy on gait biomechanics and falls risk, the absence of peripheral foot sensation (insensate feet) due to DPN plays a crucial role . SensoryDiabetic foot ulcers are a major complication of diabetes, with up to one in three patients with diabetes developing a foot ulcer in their lifetime . InfectiAn active diabetic foot ulcer necessitates patients wearing an offloading device, which could be an important risk factor for falls when patients are ambulatory due to increased weight and potential limb length discrepancies. Postural instability has been identified as a key barrier in adherence to offloading devices in patients with a diabetic foot ulcer . OffloadFalls prevention strategies have primarily focussed on the motor system component through increasing the strength of lower limb muscles ,82,83. ASensory and motor deficits caused by DPN underpin changes to gait that cause balance impairment and increase falls risk. Muscle weakness and atrophy are prevalent in diabetes patients, but most marked in those with DPN compared to their non-neuropathic counterparts and evident in both distal and proximal regions of the lower limb. Insensate feet with DPN play a fundamental role in gait alterations, leading to increased falls risk, and largely explain the high falls risk in patients with a history of diabetic foot ulcers. Although changes to gait are consistently reported in diabetes patients prior to the onset of DPN, such alterations are far more marked in patients with DPN due to insensate feet and the extent of motor impairments. Importantly, gait alterations only reach a level where they markedly impair balance in patients with DPN, explaining why DPN is an independent predictor of falls risk and why patients with DPN are up to 20-fold more likely to fall compared to an age-matched non-diabetic control. The clinical implications of DPN-related falls stretch well beyond the injurious consequences to include psychological distress, fear of falling and curtailment of physical activities linked to unsteadiness. Positive results from falls prevention studies based upon targeting both sensory and motor risk factors have been reported. However, further research is needed to optimise interventions, particularly for strategies to compensate for the DPN-related sensory deficits.


In excess of 300 million surgical procedures are undertaken worldwide each year. Despite recognition of the prevalence of postoperative pain, and improvements in pain management techniques, poorly controlled postoperative pain remains a major unresolved challenge globally. An estimated 71% and 51% of patients experience moderate to severe pain after surgery in in-patient and outpatient settings, respectively. Inadequately controlled pain after surgery is associated with significant perioperative morbidity including myocardial infarction and pulmonary complications.As many as 20–56% of patients develop chronic pain after commonly performed procedures such as hernia repair, hysterectomy, and thoracotomy. Traditional analgesics and interventions are often ineffective or partially effective in the treatment of postoperative pain, resulting in a chronic pain condition with related socio-economic impacts and reduced quality of life for the patient. Such chronic pain which occurs after surgery is referred to as Persistent Post-Surgical Pain (PPSP). The complex ecosystem that is the gastrointestinal microbiota  plays essential roles in the maintenance of the healthy state of the host. A disruption to the balance of this microbiome has been implicated not only in gastrointestinal disease but also neurological disorders including chronic pain. The influence of the gut microbiome is well documented in the context of visceral pain from the gastrointestinal tract while a greater understanding is emerging of the impact on inflammatory pain and neuropathic pain (both of which can occur during the perioperative period). The gut microbiome is an essential source for driving immune maturation and maintaining appropriate immune response. Given that inflammatory processes have been implicated in postoperative pain, aberrant microbiome profiles may play a role in the development of this type of pain. Furthermore, the microorganisms in our gut produce metabolites, neurotransmitters, and neuromodulators which interact with their receptors to regulate peripheral and central sensitisation associated with chronic pain. Microbiota-derived mediators can also regulate neuroinflammation, which is associated with activation of microglia as well as infiltration by immune cells, known to modulate the development and maintenance of central sensitisation. Moreover, risk factors for developing postoperative pain include anxiety, depression, and increased stress response. These central nervous system-related disorders have been associated with an altered gut microbiome and microbiome targeted intervention studies indicate improvements. Females are more likely to suffer from postoperative pain. As gonadal hormones are associated with a differential microbiome and pre-clinical studies show that male microbiome confers protection from inflammatory pain, it is possible that the composition of the microbiome and its by-products contribute to the increased risk for the development of postoperative pain. Very little evidence exists relating the microbiome to somatic pain. Here we discuss the potential role of the gut microbiome in the aetiology and pathophysiology of postoperative pain in the context of other somatic pain syndromes and what is known about microbe-neuron interactions. Investigations are needed to determine the specific role of the gut microbiome in this type of pain which may help inform the development of preventative interventions as well as management strategies to improve patient outcome. The International Association for the Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” . This phThe most common triggers of somatic pain are traumatic injuries and surgery. Extensive research has been conducted over decades into the nature and characteristics of surgical pain. Pre-clinical studies have been an important element of this research. Early animal models of incisional pain i.e. plantar incision in rodents representing surgical trauma , did notSensitisation  occurs in response to painful stimuli. Under physiological conditions, sensitisation is part of the normal defence mechanisms of the body against repeated noxious stimuli. It also plays an important role in the development of chronic pain. Sensitisation is a complex phenomenon of which detailed discussion is beyond the scope of this article. We refer to the excellent reviews by Woolf and Salter, and Cohen and Mao . SensitiImportant mechanisms which result in central sensitisation in the spinal cord include receptive field expansion (heterosynaptic potentiation by low frequency nociceptor inputs) and windup: repeated or intense stimulation results in release of glutamate, aspartate and different neuromodulators  with consequent slow excitatory postsynaptic potentials and NMDA / non-NMDA receptor activation, increased intracellular calcium concentration and prostaglandin formation . ModulatAnother feature of neuronal plasticity is the modification of the neuronal phenotype occurring after inflammation or axon damage . Target Persistent Post-Surgical Pain (PPSP) can affect as many as 10–50% of patients undergoing breast, cardiothoracic, limb amputation or inguinal hernia surgery . Severe,The reason why certain people develop PPSP is not completely understood; very often common analgesics used as part of multimodal analgesic regime  are ineffective in its treatment . PostopeWhen the surgical approach predisposes  or traumatic tissue handling occurs, nerve injury and consequent neuropathic pain can develop . Some ofThe prevention and treatment of persistent postsurgical pain are beyond the scope of this article. Minimally invasive and “nerve sparing” surgical techniques, preventive analgesia and novel pharmacological approaches   peripheral sensitisation due to inflammation (see above); (ii) spontaneous discharge of injured nerves (increase in Type III sodium channels and αceptors) ; and (iiceptors) . Sensiticeptors) . Neuropaceptors) . Mononeuceptors) .Acute and persistent post-surgical pain (see below) are often accompanied by a neuropathic component . This caThe practice of peripheral nerve blockade (PNBs) has increased greatly since the widespread utilisation of the ultrasound in the mid 2000s . HoweverInterestingly, it has been reported that the analgesic effect of a “single shot” nerve block appears to be limited to the first few postoperative hours. After that and up to 12–48 h postoperatively, Galos et al report that patients who have undergone PNB experience more severe pain that those who have undergone GA . SimilarThis phenomenon poses questions about the pathophysiology of RP which is likely to be distinct from that of other forms of postoperative pain. Suggested causes include nerve inflammation, the toxic effect of local anaesthetics ; the unoCurrently, there is no specific treatment for rebound pain. Opiates appear to be ineffective . CliniciOver the last three decades, the proportion of all surgery which is performed on an ambulatory basis has increased substantially; in the US more than 60% of surgical procedures are performed on outpatients . In deveMore invasive procedures performed on inpatients i.e., cardiothoracic surgery, major abdominal or orthopaedic surgeries are usually associated with the more severe postoperative pain . SuboptiIncisional pain triggers nociceptive, inflammatory and, in certain scenarios, neuropathic mechanisms. Preventive analgesia using a multimodal approach is widely practiced in perioperative medicine. However, even the application of currently available evidence in daily clinical practice can be suboptimal at times. Increased patients’ expectations and overuse of certain pharmacological agents can have deleterious effects such as opioid dependence.Postoperative pain is one of the most significant “short term fears” of patients awaiting surgery and patients’ pain experience can vary extremely, even if the intensity of surgical stimulus is similar . Most imOrthopaedic, thoracic and open abdominal surgeries account for the greatest risk of severe postoperative pain . There iThe challenge of identifying those patients who are most at risk of uncontrolled postoperative pain has compelled researchers and clinicians to examine the complex mechanism of postoperative pain and to attempt to develop new treatment strategies. The gut microbiome has been linked to several of the risk factors and mechanisms implicated in developing PPSP . Hence, The gut microbiome is the community of 100 trillion microorganisms including bacteria, archaea, yeast, helminth parasites, and viruses that inhabit our gut  and therMicrobial colonization of the human gastrointestinal tract takes place in parallel with neurodevelopment during the critical developmental window in early life . DisruptAberrations in the microbiota composition and diminished alpha diversity have been linked to the wide range of somatic disorders including type 2 diabetes and non-alcoholic fatty liver disease  as well Many factors including time of day, diet, exercise, smoking, age ; environAlthough the role of the gut microbiome is well appreciated in the context of visceral pain from the gastrointestinal tract, their involvement in other types of pain such as inflammatory pain, neuropathic pain, migraine, and opioid tolerance is only recently being recognised. Furthermore, the evidence for the involvement of the gut microbiota in pain following surgery is scarce with virtually no investigations into the predictive capacity of the composition and diversity of the microorganisms within our gut in the development of postoperative pain. Yet the mechanisms of pain and microbiome interactions gleaned from studies on other pain types can potentially be translated to the development of PPSP also.Studies in both animals and humans show that the microbiome-gut-brain axis is a bidirectional signalling network linking the brain and the gut microbiota, via various neural, neurotransmitter and molecular signalling mechanisms, such as short-chain fatty acids (SCFA), tryptophan metabolism, cortisol, and immune factors . ApproprThe neural networks involved in this communication highway include the autonomic nervous system (ANS), the vagus nerve and the enteric nervous system (ENS) within the gut . The dirThe main neuroendocrine axis, the HPA axis, also plays a vital role in the two-way signalling between the brain and the gut microbiome. Psychological stress causes release of cortisol systemically which impacts on the gut affecting the local environment including altering the microbiome composition. Furthermore, the communication between the gut microbiota and the HPA axis is complex as it is closely linked with other systems, including the gastrointestinal barrier, the immune system, the blood–brain barrier, microbial metabolites, and gut hormones . The senThe microorganisms within the gut produce a number of different hormones, neurotransmitters as well as SCFAs which can readily enter the systemic blood system to play key roles in communication between the gut microbiota and the nervous system. These are the main metabolites produced by bacterial fermentation of dietary fibre in the gastrointestinal tract and are potent regulators of host energy metabolism and immune functions .As the number of disorders with an altered gut microbiota increases this also implicates aberrant signalling pathways within the microbiome gut brain axis in these diseases which include disorders associated with altered responses to acute and chronic stress, altered nervous system functioning, and exacerbated gut inflammation disorders . This hi+, prostaglandin E2 (PGE2), tumour necrosis factor alpha (TNF-α), interleukin 1beta (IL-1β), C–C motif chemokine ligand 2 (CCL2), and chemokine (C-X-C motif) ligand 1 (CXCL1) being released from immune cells   abundance in stool samples from patients with osteoarthritis, knee pain and inflammation as assessed using magnetic resonance imaging (MRI), independent of obesity was noted . Differeles (MV) and are cPreclinical studies have used germ free (GF) mice, which are mice born via caesarean section and maintained without any microorganisms, to demonstrate that inflammatory pain requires a full gut microbiome . CompareChemotherapy induced peripheral neuropathy is a toxic side effect of some cancer treatment . RecentlAnother chemotherapy drug, paclitaxel, administered to mice, was seen to reduce the beneficial bacteria Akkermansia muciniphila which is noted for its protective effects on the gut barrier . FurtherChemotherapy-induced gut toxicity is the phrase that is now associated with the cumulative effects on the gut that are caused by chemotherapy as such as abnormalities in tight junctions, immune dysfunction and changes in the microbiota profile . TherefoNeuropathic pain is also induced by peripheral nerve trauma which can be studied in the pre-clinical setting using the rat model of spared nerve injury (SNI). Using this model, it was noted that an altered gut microbiota composition was associated with anhedonia behaviour in susceptible compared to sham-operated rats or resilient rats . Anhedonperi-operative analgesia would require empiric evidence of an association between particular gut microbiome characteristics  with improved clinical outcome or identification of particular host pathways (e.g. serotonin or endocannabinoid) which may be amenable to the influence of microbiome composition. Limited amounts of both categories of evidence exist currently; for the most part it has been acquired using animal models or through secondary outcomes of observational clinical trials. For instance, abundance of specific bacterial species in the gut microbiome are associated with symptom severity in chronic pelvic pain syndrome  provides a comprehensive view of the implications of GI surgery on the microbiome as well as the potential for the gut microbiota profile to lead to post-GI-surgical complications . DespiteLactobacillus salivarius  leads to the production of pro-inflammatory mediators such as cytokines (as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and CCL2) which can activate TRPA1, TRPV1 on nociceptive terminals and lead to neuron depolarisation and action potential along the afferent pain pathways .The immune response is activated once pathogen associated molecular patterns (PAMPs) are recognised which are localised to the surface of the microorganisms. These cell-wall constituents are relatively conserved in microorganisms including viral and bacterial nucleic acids, lipopolysaccharides (LPS), peptidoglycan (PGN), lipoteichoic acid (LTA), lipoproteins as well aBacteroides fragilis was sufficient, without the presence of the entire bacteria, to activate sensory neurons , metabolites and neurotransmitters are ligands for nociceptors . SCFA ars bromii  is a pris bromii . The fres bromii  providinSCFA play several important roles within the gut including 5-HT production, pH maintenance to limit pathogens, anti-inflammatory effects including inhibition of NK-κB and maintaining gut epithelial barrier integrity . ButyratLactobacillus and Bifidobacteria within the gut are capable of producing neurotransmitters such as 5-HT, noradrenaline, gamma-aminobutyric acid (GABA), and histamine among others (Probiotic bacteria, including g others . The rolg others  and is pg others  and we hg others  in patieg others .Faecalibacterium prausnitzii (A number of protective mechanism inbuilt into gastrointestinal tract help to modulate the gut microbiome and its influences on the host. For example, NLRC4 activates the inflammasome complex leading to the death of infected cells  which acusnitzii . This anusnitzii . While ousnitzii .This highlights that a different gastrointestinal bacterial profile can determine a host’s response to immune challenges and perhaps influence postoperative outcomes including the development of postoperative pain. A more thorough understanding of the mechanisms of direct and indirect interactions between the gut microbiome and sensory neurons is required to uncover novel therapeutic targets to inform therapeutic strategies for postoperative pain.Despite clear and substantial inadequacies, there have been no fundamental improvements in the efficacy of postoperative pain management over the past decade. Of the greater than 300 million patients who undergo surgery each year, 30–80% report moderate to severe pain in the first few days postoperatively . Much ofGiven the evidence of the influence and substantial potential of gut microbiome to modulate pain through numerous mechanisms it may well be that this complex ecosystem plays essential roles in the development of persistent pain after surgery and may offer the novel therapeutic/mechanism that is neededAs mentioned, the gut microbiome is an essential source for driving immune responses and evidence highlights its role in inflammatory pain and neuropathic pain both of which can occur during the perioperative period and may influence post-operative outcome. Furthermore, the metabolites, neurotransmitters, and neuromodulators produced by the microbiota have the capacity to directly interact with sensory receptors. Further investigations are required to determine if microbiome profiling before surgery can be included as a determinant of the risk of developing postoperative pain.This is an attractive concept as we know that the gut microbiome is amenable to interventions such as prebiotics, probiotics as well as beneficial dietary changes to include for example high fibre components. We have outlined the capacity of the gut microbiome to induce pain and touched on its role in anti-inflammatory processes as well as maintenance of gut homeostasis and epithelial barrier function. Furthermore, specific bacterial species are also capable of modulating mood and reducing anxiety and stress-related behaviour and markers.While the notion of pre-operative assessment and modulation of the gut microbiome to improve postoperative outcome is an exciting possibility a substantial amount of further research is required in order to determine the role and mechanisms of the gut microbiome in this type of pain. These future studies will inform the development of microbiome targeted interventions as well as management strategies to improve patient outcome.David Brenner: Writing - original draft, Writing - review & editing. George D. Shorten: Writing - original draft, Writing - review & editing. Siobhain M. O'Mahony: Writing - original draft, Writing - review & editing.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.