https://www.selleckchem.com/JAK.html n ages and grows. In preclinical studies, bitter compounds, including quinine, stimulate secretion of glucoregulatory hormones [e.g., glucagon-like peptide-1 (GLP-1)] and slow gastric emptying, both key determinants of postprandial glycemia. A greater density of bitter-taste receptors has been reported in the duodenum than the stomach. Thus, intraduodenal (ID) delivery may be more effective in stimulating GI functions to lower postprandial glucose. We compared effects of intragastric (IG) and ID quinine [as quinine hydrochloride (QHCl)] administration on the plasma glucose response to a mixed-nutrient drink and relations with gastric emptying, plasma C-peptide (reflecting insulin secretion), and GLP-1. Fourteen healthy men [mean±SD age 25±3y; BMI (in kg/m2) 22.5±0.5]received, on 4 separate occasions, in double-blind, randomly assigned order, 600 mgQHCl or control, IG or ID, 60min (IG conditions) or 30min (IG conditions) before a mixed-nutrient drink. Plasma glucose (primary outcome) and hormones were measured before, and In healthy men, IG and ID quinine administration similarly lowered plasma glucose, increased plasma insulin and GLP-1, and slowed gastric emptying. These findings have potential implications for lowering blood glucose in type 2 diabetes. This study was registered as a clinical trial with the Australian New Zealand Clinical Trials at www.anzctr.org.au as ACTRN12619001269123. In healthy men, IG and ID quinine administration similarly lowered plasma glucose, increased plasma insulin and GLP-1, and slowed gastric emptying. These findings have potential implications for lowering blood glucose in type 2 diabetes. This study was registered as a clinical trial with the Australian New Zealand Clinical Trials at www.anzctr.org.au as ACTRN12619001269123. Prior studies of adults with constipation or diarrhea suggest that dietary intake, physical activity, and stress may affect stool consistency. However, the influence of the