A gut-microbiota–friendly diet after bariatric surgery to help eating habits and taste
Randomised Controlled Trial Evaluating the Impact of a Pro-diversity Gut Microbiota Diet on Gut Microbiota, Eating Behaviour and Sensory Function in Patients Who Have Undergone Bariatric Surgery
NA · Hospices Civils de Lyon · NCT07268508
This tests whether a diet designed to increase gut microbiota diversity helps adults who have had sleeve gastrectomy or Roux-en-Y gastric bypass keep weight off, change food preferences and taste/smell, and improve gut-related health compared with standard nutrition counseling.
Quick facts
| Phase | NA |
|---|---|
| Study type | Interventional |
| Enrollment | 60 (estimated) |
| Ages | 25 Years to 65 Years |
| Sex | All |
| Sponsor | Hospices Civils de Lyon (other) |
| Locations | 3 sites (Lyon and 2 other locations) |
| Trial ID | NCT07268508 on ClinicalTrials.gov |
What this trial studies
Adults aged 25–65 undergoing sleeve gastrectomy or Roux-en-Y gastric bypass are assigned to receive either nutritional counseling that promotes gut microbiota diversity or standard nutritional counseling after surgery. The interventions focus on post-operative dietary guidance and follow participants for one year. Outcomes include measures of gut microbiota diversity, food preferences and eating behaviors, sensory profiles (taste and smell), fasting and postprandial gut and digestive hormones, cardiometabolic markers, mental health, and physical activity. The goal is to link dietary patterns that favor microbiota diversity with long-term weight maintenance and changes in sensory and metabolic function after bariatric procedures.
Who should consider this trial
Good fit: Adults aged 25–65 undergoing sleeve gastrectomy or Roux-en-Y gastric bypass with BMI ≥40 kg/m² or BMI ≥35 kg/m² with at least one obesity-related comorbidity (excluding type 2 diabetes), who can consent, use effective contraception if applicable, and live within about 1.5 hours of the study hospital.
Not a fit: People with type 2 diabetes, inflammatory gastrointestinal disease, known gastroparesis, major prior GI surgeries, significant organ failure, pregnant or breastfeeding women, claustrophobic individuals, or those on recent obesity medications are excluded and may not benefit from this protocol.
Why it matters
Potential benefit: If successful, this approach could help people maintain weight loss after bariatric surgery and improve eating behavior, taste or smell, and related metabolic markers.
How similar studies have performed: Prior research links gut microbiota composition to weight regulation and post-bariatric changes, but dietary programs specifically designed to boost microbiota diversity after bariatric surgery are relatively novel and not yet proven in large trials.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Between 25 and 65 years old * Undergoing either sleeve gastrectomy or Roux-en-Y gastric bypass * With grade 3 obesity (BMI≥40 kg/m²) or with BMI≥35 kg/m² and at least one comorbidity likely to be improved after surgery, with the exception of type 2 diabetes * Signed consent form * Living less than an hour and 30 minutes from the hospital * Presence of effective and stable contraception for women of childbearing potential Exclusion Criteria: * Type 2 diabetes * Presence of a contraindication to bariatric surgery * Presence of gastrointestinal pathologies with an inflammatory component, known gastroparesis, total gastrectomy, colectomy, exocrine pancreatic insufficiency, known endocrine pathologies inducing hyperglycaemia (uncontrolled dysthyroidism, acromegaly, hypercorticism, etc.), severe chronic renal insufficiency (\< 30mL/min), or hepatocellular insufficiency * Claustrophobic * Pregnant or breastfeeding women * Taking an obesity treatment 3 months before surgery * Taking a corticoids, immunosuppression, anabolizing, or growing hormones, antibody treatments less than 3 months before inclusion * Daily taking of laxatives or drugs that can strongly interfere with the composition of the intestinal microbiota. If taken sporadically, the patient can be included at a distance (3 weeks) from the laxatives taken. * Specific diets (vegetarian, vegan or without gluten) * No French speaker * Already included in other study * Donated blood in the last two months * Without freezer access * With allergy or intolerance to food propose in ad libitum buffet
Where this trial is running
Lyon and 2 other locations
- Hospital Edouard Herriot, digestive surgery department — Lyon, France (RECRUITING)
- Centre de recherche en nutrition humaine de Rhône-Alpes — Pierre-Bénite, France (NOT_YET_RECRUITING)
- Hôpital Lyon sud, Endocrinology Diabetes Nutrition department — Pierre-Bénite, France (NOT_YET_RECRUITING)
Study contacts
- Study coordinator: Julie-Anne NAZARE
- Email: julie-anne.nazare@univ-lyon1.fr
- Phone: +33 6 88 87 09 62
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Obesity, Bariatric Surgery, Bariatric surgery, gut microbiota, sensory alteration, food preferences, weight loss maintenance