An extract of hops (Humulus lupulus L.) modulates gut peptide hormone secretion and reduces energy intake in healthy weight men: a randomised, cross-over clinical trial

Abstract

ABSTRACTBackgroundGastrointestinal enteroendocrine cells express a range of chemosensory receptors involved in detecting the chemical composition of food during digestion. These receptors, including bitter taste receptors (T2Rs), may play an important role in regulating gut function and appetite.ObjectiveTo establish the ability of Amarasate®, a bitter supercritical CO2 extract of hops (Humulus lupulus L.) to modify acute energy intake, appetite and hormonal responses and establish a site of action.DesignNineteen healthy-weight (BMI = 23.5 ± 0.3 kg/m2) male volunteers completed a randomised three-treatment, double blind, cross-over study with a 1 week washout between treatments. Overnight-fasted participants were cannulated and provided with a standardised 2 MJ breakfast meal at 0900h. Treatments comprised a vehicle control (Placebo) or 500 mg of hops extract administered in either delayed release capsules (Duodenal) at 1100 h or quick release capsules (Gastric) at 1130 h. Ad libitum energy intake was recorded at an outcome meal (1200 h) and afternoon snack (1400 h), with blood samples taken and subjective ratings of appetite, gastrointestinal discomfort, vitality, meal palatability and mood assessed throughout the day.ResultsCompared with placebo, both gastric and duodenal treatments significantly reduced (p < 0.05) total ad libitum energy intake by 911 ± 308 kJ and 944 ± 309 kJ, respectively. Both gastric and duodenal treatments significantly increased (p < 0.05) pre-meal ghrelin and post-prandial CCK, GLP-1 and PYY responses while reducing postprandial insulin, GIP and PP secretion with no significant impact on glycemia. In addition, gastric and duodenal treatments produced small but significant (p < 0.05) changes in vitality and gastrointestinal discomfort (e.g. nausea, bloating, abdominal discomfort) with mild-moderate adverse GI symptoms reported in the gastric treatment only. However, no significant treatment effects were observed for any subjective measures of appetite or meal palatability.ConclusionBoth gastric and duodenal delivery of Amarasate® modulate the release of hormones involved in appetite and glycaemic regulation, providing a potential “bitter brake” on energy intake in healthy-weight men.