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

Inclusion Criteria: 1. Males or females aged 18 to 60 years, inclusive, at enrollment. 2. BMI of ≥18.5 but \<30 kg/m2. 3. Healthy, as determined based on self-reported medical history. 4. No planned change in diet or medical interventions during the study. 5. Willing to collect fecal samples and retrieve sampling capsules from feces. 6. Able to understand and to sign a written informed consent prior to study enrollment. 7. Willing and able to comply with the requirements for participation in this study. Exclusion Criteria: 1. 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). 2. 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. 3. 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. 4. History of chronic constipation (defined as having less than 3 bowel movements per week) in the past month, as reported by the participant. 5. Any history of obstructive symptoms in the previous 3 months prior to enrollment, as reported by the participant. 6. Diagnosis of any organic motility disorder, including gastroparesis, intestinal pseudo-obstruction, systemic sclerosis, Ogilvie's syndrome, as reported by the participant. 7. Diagnosis of any malabsorption disorder (i.e. malabsorption syndrome, lactose malabsorption), as reported by the participant. 8. History of oropharyngeal dysphagia or other swallowing disorder with a risk of aspiration of the capsule, as reported by the participant. 9. Any concurrent cancer diagnosis, as reported by the participant. 10. Any cancer treatment within the past year, as reported by the participant. 11. History of known abdominal or pelvic radiation treatment at any time in the past, as reported by the participant. 12. 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. 13. Antibacterial/antifungal therapy in the past 3 months prior to enrolment, as reported by the participant. 14. 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. 15. Underwent colon cleanse or bowel preparation in the 2 weeks prior to enrollment, as reported by the participant. 16. Scheduled for an MRI at any time during the study duration. Potential participants may be eligible to participate once their MRI procedure is completed. 17. 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). 18. 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. 19. Currently participating in another interventional study. 20. Family or hierarchical relationships with the research team members.