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
