Healthy Stool Volunteer Donors for Fecal Microbiota Transplantation Trials

Inclusion Criteria: \- Age ≥ 18 years and \< 50 years * 17 kg/m² \< body mass index \< 30 kg/m² * Regular bowel movement defined as at least 1 stool every other day and maximum 2 stools per day * Subject with health insurance (AME excepted) * Informed written consent Exclusion Criteria: Definitive non-inclusion criteria: 1. Infectious risk : \- Known HIV, HBV, HCV, HTLV infection \- Residence of more than 2 years in the intertropics zone within the previous 5 years \- Hospitalization abroad for more than 24 hours in the last 12 months (including a member of the healthy volunteers donor's entourage) \- Risk factors for Creutzfeldt-Jakob disease (history: treatment with extractive growth hormone, a family case of transmissible spongiform subacute encephalopathy, surgery with opening of the dura or neurosurgery or invasive brain exploration before 1 January 1995, stay in United Kingdom for a duration greater than 1 year cumulatively between 1980 and 1996 or the presence of neurological or neuropsychiatric scalable recent clinical signs) * Previous history of typhoid fever, tuberculosis and malaria * Past or current injection drug user or regular use of other drug 2. Gastrointestinal disease: \- Personal or 1st degree family history of: inflammatory bowel disease or celiac disease \- Personal history of irritable bowel syndrome, idiopathic chronic constipation or chronic diarrhea \- Previous history of gastrointestinal neoplasia or polyps \- Family history of 1st degree gastrointestinal neoplasia or polyps before age 60 3. 1st degree family history of one of the following autoimmune or inflammatory disease : inflammatory arthritis, psoriasis, multiple sclerosis, type I diabetes, spondylitis, lupus and Basedow disease \- If family history unknown in the first degree, the donor is not eligible 4. Previous history of : * Subject prone to hemorrhoids (at least 1 event within the previous 1 year) * Subject with an active chronic illness (except active chronic mild allergic disease o (example: allergic rhinitis, chronic eczema…)) * Diagnosis of Gilbert's syndrome done by screening is not a chronic disease. The healthy volunteer donor will therefore remain eligible. * Serious allergy requiring hospitalization within the previous 12 months * Curative long-term treatment * Severe allergy requiring hospitalization in the last 12 months * Allogeneic human or animal tissue or organ transplant * 5- Factors that may affect the composition of the intestinal microbiota: * Special Diet (example: gluten-free...) * Lactose-free, vegetarian and vegan diets are permitted. * Pregnancy or breastfeeding * Taking immunosuppressants (eg calcineurin inhibitors, corticosteroids, biological agents, etc.) * Antineoplastic chemotherapy 6- Subject under legal protection 7- Participation in any other interventional study except studies for stool donation Temporary non-inclusion criteria 1. Infectious risk : * Unprotected sexual intercourse with a new partner in the previous 4 months and/or sexual intercourse with several different persons within the previous 4 months * sexual partner who has had more than 1 partner within the previous 4 months and/or * sexual transmitted infection within the previous 4 months (healthy volunteer donor himself or sexual partner) * Sexual relationship in exchange for money or drugs in the last 12 months. (healthy volunteer donor himself or sexual partner) * Sexual relationship with a partner with positive serology for HIV, viral hepatitis B or C, in the last 6 months. * Sexual relationship with a partner who has used intravenous drugs, doping substances * Hospitalization abroad for more than 24 hours in the last 12 months (healthy volunteer or entourage) * Travelling within the previous 3 months except : Germany, Austria, Belgium, Spain, Finland, Ireland, Italia, Luxembourg, Netherland, Portugal, Greece, Slovenia, Cyprus, Malta, Slovakia, Estonia , Bulgaria, Croatia , Hungary, Latvia , Lithuania, Poland , Romania, Czech Republic, the United Kingdom, Denmark, Norway, Sweden, Switzerland, USA or Canada. * Blood transfusion, piercing (including earrings) or tattoo within the previous 4 months * Surgery (all types) or hospitalization within the previous 4 months * Person living under the same roof with an infectious or contagious disease (i.e who have been hospitalized) within the previous 4 months * Blood exposure accident (for wound, pricking or projection ...) within the previous 4 months * Dental care within the previous 7 days * Gastroenteritis within the previous 3 months (defined by acute onset of diarrhea (\> 3 soft or liquid stools per day) and duration \< one week) * Episode of infection or skin infection/lesion within the previous 15 days 2-Risk linked to Covid-19 * Confirmed infection in the previous 28 days (after symptoms have ceased) * Clinical signs of suspected infection (chill, cough, fever, dyspnea, myalgia, asthenia, malaise, pharyngeal pain, anosmia , ageusia, rhinorrhea, chest pain, headache, diarrhea) in the previous 28 days (after the end of symptoms) * Having been in risky contact (according to the definition of Santé Publique France with a person whose infection is confirmed or suspected: "14 days after the last risky contact: if the recommended screening tests in the event of risky contact between D15-D28 are negative "In the 28 days preceding inclusion in the absence of a screening test. Healthcare professionals using recommended protective measures with COVID patients are not considered high-risk contacts 3- Monkeypox risk * Confirmed or suspected infection within the previous 42 days ( after beginning of symptoms) * Risky contact with a person with confirmed or suspected infection within the previous 21 days (from the date of last contact) * Person who received the vaccine Imvanex within the previous 28 days ( after the last injection). 4- vaccination in the previous 15 days 5- Factors that may affect the composition of the intestinal microbiota: * Taking antibiotic or antifungal (oral) in the previous 3 months before donation * Taking non-steroidal anti-inflammatory drugs (oral) in the previous month before donation * Taking corticosteroids (oral) in the previous 4 weeks before donation. Corticosteroids allowed if taken more than 4 weeks before donation. and not for an autoimmune or inflammatory disease. Temporary or permanent exclusion criteria: \- At each visit of the donation period, the temporary or definitive exclusion criteria (identical to the temporary or definitive non-inclusion criteria) will be rechecked