Stool donation to see how dairy phages and antibiotics change the gut microbiome

Collection of Stool From Healthy Donors for the ex Vivo Study of Shifts of Microbiome Induced by Dairy Phages and Antibiotics: a Model of Bacteria/Host Interaction

This project tests whether bacteriophages from dairy products and antibiotics change the mix of gut microbes in healthy adults.

Quick facts

• Study type: Observational
• Enrollment: 4 (estimated)
• Ages: 18 Years to 60 Years
• Sex: All
• Sponsor: Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (other)
• Locations: 1 site (Jouy-en-Josas)
• Trial ID: NCT07212400 on ClinicalTrials.gov

What this trial studies

Researchers will collect stool from healthy adult donors and use ex vivo laboratory models to expose those samples to bacteriophages found in dairy and to selected antibiotics. Microbial community composition and diversity will be measured before and after exposures using sequencing and microbiological methods. The approach models bacteria–host interactions outside the body to identify shifts in bacterial populations driven by phages or antibiotics. Findings aim to clarify how food-associated phages might influence recovery or disruption of the gut microbiome.

Who should consider this trial

Good fit: Ideal participants are healthy adults aged 18–60 who eat a varied omnivorous diet, are not pregnant or breastfeeding, have not used antibiotics, anti-inflammatories, immunosuppressants, or microbial supplements in the past 3 months, and have no diagnosed acute or chronic gastrointestinal, metabolic, immune, or inflammatory conditions.

Not a fit: Those unlikely to receive benefit include people with chronic gastrointestinal or systemic diseases, pregnant or breastfeeding women, recent users of antibiotics or probiotics/prebiotics, individuals on restrictive diets (e.g., vegetarian or vegan), and minors.

Why it matters

Potential benefit: If successful, this work could identify phage–food interactions that help restore microbiome diversity and inform dietary or phage-based strategies to prevent or correct dysbiosis.

How similar studies have performed: Prior studies demonstrate that bacteriophages can shift bacterial populations and influence microbiome composition, but using dairy-derived phages in ex vivo models is a relatively novel application.

Eligibility criteria

Inclusion Criteria:

* Age ≥ 18 years and ≤ 60 years
* Varied and balanced omnivorous diet

Exclusion Criteria:

* Vegetarian, vegan, or restrictive diet
* Use of medications (antibiotics, anti-inflammatory drugs, immunosuppressants, and/or probiotics, prebiotics, or synbiotics), either as drugs or dietary supplements, within the 3 months prior to sample collection
* Pregnant and/or breastfeeding women
* Presence of an acute or chronic disease (gastrointestinal, metabolic, immune, or inflammatory), diagnosed or suspected
* Colonoscopy within the past 3 months
* Known food allergy or intolerance (e.g., gluten, lactose, FODMAPs) that may alter the usual diet and/or microbiota composition
* Individuals under legal protection (guardianship, trusteeship, etc.)

Where this trial is running

Jouy-en-Josas

• Metagenopolis — Jouy-en-Josas, France (RECRUITING)

Study contacts

• Study coordinator: Christian Morabito

Conditions: General Population, phages, antibiotics