None listed
Conditions
Brief summary
Recent studies have demonstrated that specific nutrients, including lauric acid and L-tryptophan, have energy intake-suppressant and blood glucose-regulatory effects via several pathways, including stimulation of gut hormones and motility, and the slowing of gastric emptying. We aim to investigate the hypothesis that the combined intraduodenal administration of lauric acid and tryptophan, compared with the individual nutrients, will more potently stimulate gut functions, including gut hormones, and gastric emptying, associated with reduced postprandial blood glucose
Interventions
On each study occasion, participants will attend the laboratory at ~ 08:00 hr, after fasting overnight, and will be intubated, via an anaesthetised nostril, with a small-diameter nasoduodenal manometric catheter consisting of 16 channels plus an infusion port. The catheter will be allowed to pass through the stomach and into the duodenum. Once the catheter is positioned correctly, with the sleeve sensor straddling the pylorus, fasting motility will be observed until a phase III of the interdiges
On each study occasion, participants will attend the laboratory at ~ 08:00 hr, after fasting overnight, and will be intubated, via an anaesthetised nostril, with a small-diameter nasoduodenal manometric catheter consisting of 16 channels plus an infusion port. The catheter will be allowed to pass through the stomach and into the duodenum. Once the catheter is positioned correctly, with the sleeve sensor straddling the pylorus, fasting motility will be observed until a phase III of the interdigestive migrating motor complex occurs. Immediately following the cessation of phase III, and during phase I, an intravenous cannula will be inserted for blood sampling (to measure gut hormones and blood glucose). At t = -41 min, participants will complete a VAS questionnaire, then at t = -31 min, a baseline blood sample and breath sample (to measure gastric emptying), will be taken, and participants will complete another VAS questionnaire. At t = -31 min, the infusion will commence, and continue until t = 15 min. At t = -1 min, participants will be given a mixed-nutrient drink (containing 500 kcal, 74 g carbohydrates) to consume within 1 min, which will be marked with carbon-13 acetate to facilitate the measurement of gastric emptying using 13C-breath test. - Blood samples will be taken at the following time points: t = -31, -15, 0, 10, 20, 30, 45, 60, 90, 120 min. - Breath samples will be taken at the following time points: t = -31, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180 min. - VAS questionnaires will be complete at the following time points: t = -41, -31, -15, 0, 10, 20, 30, 45, 60, 75, 90, 105, 120 min. - Antropyloroduodenal motility will be continuously measured from t = -31 to 120 min. At t = 120 min, the intraduodenal tube will be removed and breath testing will continue until t = 180 min. Participants will then be served a light lunch, consisting of a sandwich, fruit/museli bar, and water, and then allowed to leave the laboratory.
Sponsors
Professor 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
Healthy lean (BMI 19 - 25 kg/m2) male volunteers aged between 18-55 years, non-smokers, and without significant illness will be included in the study.
Exclusion criteria
Significant upper GI symptoms or history of GI disease or surgery Current gallbladder or pancreatic disease Cardiovascular or respiratory disease 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 (e.g. domperidone and cisapride, anticholinergic drugs (e.g. atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St Johns Wort etc.) Lactose intolerance/ other food allergy(ies) Individuals with low ferritin levels (males <30 ng/mL), or who have donated blood in the 12 weeks prior to taking part in the study High performance athletes Current intake of > 2 standard drinks on > 5 days per week (>140g/week) Current smokers of cigarettes/cigars/marijuana Current intake of any illicit substance Vegetarians Inability to comprehend study protocol Restrained eaters (score > 12 on the three factor eating questionnaire)
Outcome results
None listed