The Bitter Taste Receptor Agonist Quinine Reduces Calorie Intake and Increases the Postprandial Release of Cholecystokinin in Healthy Subjects

Abstract

Background/AimsBitter taste receptors are expressed throughout the digestive tract. Data on animals have suggested these receptors are involved in the gut hormone release, but no data are available in humans. Our aim is to assess whether bitter agonists influence food intake and gut hormone release in healthy subjects. MethodsTwenty healthy volunteers were enrolled in a double-blind cross-over study. On 2 different days, each subject randomly received an acid-resistant capsule containing either placebo or 18 mg of hydrochloride (HCl) quinine. After 60 minutes, all subjects were allowed to eat an ad libitum meal until satiated. Plasma samples were obtained during the experiment in order to evaluate cholecystokinin (CCK) and ghrelin levels. Each subject was screened to determine phenylthiocarbamide (PTC) tasting status. ResultsCalorie intake was significantly lower when subjects received HCl quinine than placebo (514 ± 248 vs 596 ± 286 kcal; P = 0.007). Significantly higher CCK ΔT90 vs T0 and ΔT90 vs T60 were found when subjects received HCl quinine than placebo (0.70 ± 0.69 vs 0.10 ± 0.86 ng/mL, P = 0.026; 0.92 ± 0.75 vs 0.50 ± 0.55 ng/mL, P = 0.033, respectively). PTC tasters ingested a significantly lower amount of calories when they received HCl quinine compared to placebo (526 ± 275 vs 659 ± 320 kcal; P = 0.005), whereas no significant differences were found for PTC non-tasters (499 ± 227 vs 519 ± 231 kcal; P = 0.525).Paolo Andreozzi, et al Journal of Neurogastroenterology and Motility 512 ConclusionsThis study showed that intra-duodenal release of a bitter compound is able to significantly affect calorie intake and CCK release after a standardized meal. Our results suggest that bitter taste receptor signaling may have a crucial role in the control of food intake. (J Neurogastroenterol Motil 2015;21:511-519)

Intragastric infusion of the bitter tastant quinine suppresses hormone release and antral motility during the fasting state in healthy female volunteers

“…Van Avesaat et al . reported no significant change in CCK, GLP‐1, and PYY after intraduodenal infusion of quinine, while another study did report an increase in postprandial CCK release after intradoudenal quinine administration . Ghrelin release was not altered after intragastric administration of DB in humans .…”

Appetite‐Inducing Effects of Homoeriodictyol: Two Randomized, Cross‐Over Interventions

“…In addition to the bitter masking effect, in vitro experiments carried out in our working group have shown that NaHED, the more water soluble sodium salt of HED, may also have the potential to stimulate mechanisms regulating hunger as it affected glucose uptake and serotonin release in Caco‐2 cells . Another recent study demonstrated that bolus administration of 18 mg quinine hydrochloride, a bitter taste receptor agonist, reduced ad libitum calorie intake in healthy adults, providing evidence that bitter taste receptors may be involved in the regulation of food intake. We, therefore, hypothesized that bitter‐masking agents, like HED, might exert opposite effects.…”

Intragastric infusion of denatonium benzoate attenuates interdigestive gastric motility and hunger scores in healthy female volunteers

“…Study design 69 The current study consisted of 5 independent protocols studying the following parameters: provided 80% power to detect significant differences of 15% with an alfpha of 0.05 (13,23,92 24). Based on the results obtained from the lingual (study 1) and gastrointestinal (study 2) 93 bitter sensitivity studies it was decided to only include female participants for the last 3 study 94 protocols.…”