The endocrine effects of bitter tastant administration in the gastrointestinal system: intragastric versus intraduodenal administration.
Bitter tastants are recently introduced as potential hunger-suppressive compounds, the so-called "Bitter pill." However, the literature about bitter administration lacks consistency in methods and findings. We want to test whether hunger ratings and hormone plasma levels are affected by: 1) the site of administration: intragastrically (IG) or intraduodenally (ID), 2) the bitter tastant itself, quinine hydrochloride (QHCl) or denatonium benzoate (DB), and 3) the timing of infusion. Therefore, 14 healthy, female volunteers participated in a randomized, placebo-controlled six-visit crossover study. After an overnight fast, DB (1 µmol/kg), QHCl (10 µmol/kg), or placebo were given IG or ID via a nasogastric feeding tube. Blood samples were taken 10 min before administration and every 10 min after administration for a period of 2 h. Hunger was rated at the same time points on a visual analogue scale. ID bitter administration did not affect hunger sensations, motilin, or acyl-ghrelin release compared with its placebo infusion. IG QHCl infusion tended to suppress hunger increase, especially between 50 and 70 min after infusion, simultaneously with reduced motilin values. Here, acyl-ghrelin was not affected. IG DB did not affect hunger or motilin, however acyl-ghrelin levels were reduced 50-70 minutes after infusion. Plasma values of glucagon-like peptide 1 and cholecystokinin were too low to be properly detected or to have any physiological relevance. In conclusion, bitter tastants should be infused into the stomach to reduce hunger sensations and orexigenic gut peptides. QHCl has the best potential to reduce hunger sensations, and it should be infused 60 min before food intake.NEW & NOTEWORTHY Bitter tastants are a potential new weight-loss treatment. This is a noninvasive, easy approach, which should be received with considerable enthusiasm by the public. However, literature about bitter administration lacks consistency in methods and findings. We summarize how the compound should be given based on: the site of administration, the best bitter compound to use, and at what timing in respect to the meal. This paper is therefore a fundamental step to continue research toward the further development of the "bitter pill."
['Verbeure|Wout|W|', 'Deloose|Eveline|E|', 'Tóth|Joran|J|', 'Rehfeld|Jens F|JF|', 'Van Oudenhove|Lukas|L|', 'Depoortere|Inge|I|', 'Tack|Jan|J|']
D002766:Cholecystokinin D018592:Cross-Over Studies D004386:Duodenum D005260:Female D054439:Ghrelin D052216:Glucagon-Like Peptide 1 D006801:Humans D006815:Hunger D007441:Intubation, Gastrointestinal D009037:Motilin D036361:Peptide Hormones D010919:Placebos D000644:Quaternary Ammonium Compounds D011803:Quinine D016037:Single-Blind Method D013270:Stomach D013649:Taste D015431:Weight Loss D055815:Young Adult
quinine hydrochloride denatonium benzoate hunger sensations motilin ghrelin