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Effects of intragastric administration of quinine (bitter agonist), on appetite and gut hormone release in healthy, lean volunteers.

Effects of intragastric administration of quinine (bitter agonist), on appetite and energy intake, and gut hormone release, in healthy, lean volunteers.

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12618000814279
Enrollment
12
Registered
2018-05-11
Start date
2018-05-28
Completion date
2019-01-04
Last updated
2019-08-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

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 energy intake at a subsequent ad libitum buffet style meal, plasma gut hormone concentrations, and appetite perceptions.. 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 effects of an intragastric administration of quinine on appetite and energy intake. 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) followed 30 min later by an ad libitum buffet style meal. Subjects will receive one infusion per study visit. Study visits will be separated by 3-7 days. For each study visit a baseline blood sample, an

This trial aims to assess the effects of an intragastric administration of quinine on appetite and energy intake. 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) followed 30 min later by an ad libitum buffet style meal. Subjects will receive one infusion per study visit. Study visits will be separated by 3-7 days. For each study visit a baseline blood sample, and Visual analogue Scale (VAS) questionnaire 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 0 min, a further blood sample will be collected and VAS completed. At t = 0 min, subjects will be presented with a cold, buffet-style meal. Subjects will be allowed 30 minutes to freely consume the buffet meal until comfortably full. At t = 30, 60 and 90 min further blood samples will be taken, and VAS administered at t = 30, 45 60, 75 and 90 min,

Sponsors

Christine Feinle-Bisset
Lead SponsorIndividual

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 12 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

Source: ANZCTR · Data processed: Feb 4, 2026