The Effects of an Oral Nutritional Intervention on the Small Intestine Microbiome

Inclusion criteria

• Males or females aged 18 to 60 years, inclusive, at enrollment.
• BMI of ≥18.5 but <30 kg/m2.
• Healthy, as determined based on self-reported medical history.
• No planned change in diet or medical interventions during the study.
• Willing to collect fecal samples and retrieve sampling capsules from feces.
• Able to understand and to sign a written informed consent prior to study enrollment.
• Willing and able to comply with the requirements for participation in this study.

Exclusion criteria

• Prior or suspected gastrointestinal disease (as reported by the participant) which, in the investigator/study doctor's opinion, would lead to fistula formation, intestinal stricturing, or obstruction leading to a risk of capsule non-excretion (i.e. achalasia, active ulcer disease, eosinophilic esophagitis, Crohn's disease, ulcerates colitis, celiac disease, irritable bowel syndrome, stenosis of the GI tract).
• Any prior gastrointestinal surgery (as reported by the participant) which, in the investigator/study doctor's opinion, would lead to intestinal stricturing or obstruction leading to a risk of capsule non-excretion (i.e. previous esophageal, gastric, small intestinal, or colonic surgery). Note: appendectomy, cholecystectomy, hysterectomy, oophorectomy, hemorrhoid surgery more than 3 months prior to enrollment are acceptable.
• History of chronic diarrhea (defined as Bristol stool scale 5 to 7; or persistent or recurrent loose or watery stools lasting for more than 4 weeks), as reported by the participant.
• History of chronic constipation (defined as having less than 3 bowel movements per week) in the past month, as reported by the participant.
• Any history of obstructive symptoms in the previous 3 months prior to enrollment, as reported by the participant.
• Diagnosis of any organic motility disorder, including gastroparesis, intestinal pseudo-obstruction, systemic sclerosis, Ogilvie's syndrome, as reported by the participant.
• Diagnosis of any malabsorption disorder (i.e. malabsorption syndrome, lactose malabsorption), as reported by the participant.
• History of oropharyngeal dysphagia or other swallowing disorder with a risk of aspiration of the capsule, as reported by the participant.
• Any concurrent cancer diagnosis, as reported by the participant.
• Any cancer treatment within the past year, as reported by the participant.
• History of known abdominal or pelvic radiation treatment at any time in the past, as reported by the participant.
• Any cardiovascular, endocrine, renal, liver, or other chronic disease likely to affect motility (i.e. diabetes mellitus, concurrent biliary tract stones, kidney stones, etc.), as reported by the participant.
• Antibacterial/antifungal therapy in the past 3 months prior to enrolment, as reported by the participant.
• Use of any medications or supplements that could substantially alter gastrointestinal acidity, motor function, or microbiota (e.g. proton pump inhibitors, H2 receptor antagonists, opioids, prokinetics, anticholinergics, laxatives) in the past 4 weeks prior to enrollment, as reported by the participant.
• Underwent colon cleanse or bowel preparation in the 2 weeks prior to enrollment, as reported by the participant.
• Scheduled for an MRI at any time during the study duration. Potential participants may be eligible to participate once their MRI procedure is completed.
• Females of childbearing age who are pregnant or lactating, as reported by the participant (should an X-ray be required for confirmation of capsule passage; a urine pregnancy test will be administered beforehand).
• Alcohol intake higher than 2 servings per day over a week (for males), or more than 1 serving per day over a week (for females), as reported by the participant. A serving is 0.3 dl of strong alcohol, 1 dl of wine, or 3 dl of beer.
• Currently participating in another interventional study.
• Family or hierarchical relationships with the research team members.