None listed
Conditions
Brief summary
The purpose of this trial is to investigate the dose-related effects of intragastric administration of the bitter agonist, quinine, a non-nutritive (calorie-free) compound, on gastric emptying, gut and gluco-regulatory hormone, postprandial blood glucose and appetite responses to a subsequent meal.. The relationship between outcomes and the ability to detect bitter in the oral cavity will also be investigated. We have found previously that specific dietary nutrients, when given into the small intestine in small amounts (and so not contributing significantly to overall energy intake) have the unique ability to substantially stimulate gastrointestinal functions leading to marked energy intake suppression and improvements in postprandial blood glucose. There has been a recent interest in the effects of bitter compounds, some of which also occur in the diet, including thio-urea compounds in certain vegetables or fruit, or quinine in tonic water, with reported effects on gut functions and energy intake suppression. This study aims to characterise the dose-related effects of quinine, when delivered intragastrically, in an effort to identify an optimal dose for beneficial effect on the outcomes mentioned herein. This may then guide future research to evaluate hypotheses that observed effects may be further enhanced by combining nutrients with quinine
Interventions
This trial aims to assess the dose-relative effects of intragastric administration of quinine on gastric emptying, gut and gluco-regulatory hormones, postprandial blood glucose, and appetite in response to a mixed-nutrient drink.
In this study, subjects will receive, in randomized, double-blind fashion, an intragastric bolus infusion (21 mL) of i) 275 mg quinine; ii) 600 mg quinine and iii) saline (control) 30 min before 350 ml (500 kcal) of a mixed-nutrient drink to evaluate the effects on gas
This trial aims to assess the dose-relative effects of intragastric administration of quinine on gastric emptying, gut and gluco-regulatory hormones, postprandial blood glucose, and appetite in response to a mixed-nutrient drink. In this study, subjects will receive, in randomized, double-blind fashion, an intragastric bolus infusion (21 mL) of i) 275 mg quinine; ii) 600 mg quinine and iii) saline (control) 30 min before 350 ml (500 kcal) of a mixed-nutrient drink to evaluate the effects on gastric emptying, and the hormone, postprandial blood glucose, and appetite, responses to the mixed-nutrient drink. Study visits will be separated by 3-7 days and subjects will receive one infusion per visit. For each study visit a baseline blood sample, VAS, and breath sample will be collected (t = -31). The infusion will then be administered using a feeding tube, at the end of which will be marked as t=-30. At t = -20, -10, and -1 min further blood samples will be collected and VAS completed. At t = -1 min, subjects will consume, within 1 minute, a mixed-nutrient drink (Resource Plus, 500 kcal, 350 ml) labeled with 100 mg of 13C-acetate for measurement of gastric emptying by breath sampling, and 3g 3-OMG for measurement of glucose absorption. Blood samples and VAS will be taken every 15 minutes, and breath samples will be taken every 5 min, over the next hour (t = 0 to 60 min). Over the following hour, VAS and blood samples will be collected every half hour (t = 90, 120), and breath samples collected every 15 min (t = 75, 90, 105, 120). In addition, gastric emptying will be evaluated using 2D ultrasound by measuring antral area at baseline and every 5 min after ingestion of the mixed liquid meal (t=0-30 min) and then at 15-min intervals (t=30-120 min)
Sponsors
Christine Feinle-Bisset
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
Male
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
A total of 15 healthy, lean (BMI 19-25 kg/m2) male subjects, aged between 18 - 55 years, will be included in each study part.
Exclusion criteria
Significant gastrointestinal symptoms, disease or surgery; Current gallbladder or pancreatic disease; Cardiovascular or respiratory diseases; . Any other illnesses as assessed by the investigator (including chronic illnesses not explicitly listed above); Use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, gastrointestinal function, body weight or appetite (eg domperidone and cisapride, anticholinergic drugs (eg atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St Johns Wort etc.); Individuals with low ferritin levels (less than 30 ng/mL), or who have donated blood in the 12 weeks prior to taking part in the study; Lactose intolerance/other food allergy(ies); Vegetarians; Restrained eaters (score >12 on the three factor eating questionnaire); Current intake of greater than 2 standard drinks on greater than 5 days per week; Current smokers of cigarettes/cigars/marijuana; Current intake of any illicit substance; High performance athletes; Inability to comprehend study protocol; Unable to tolerate naso-gastric tube.
Outcome results
None listed