The goal of this study is to optimise the pre-analytical process for metagenomic analysis of the microbiota in comparison with the current reference technique.

A comparative evaluation will be performed between the following and the reference standard (quickly frozen fresh stool):

i) faecal sample collection devices commonly used in France and abroad for metagenomics, metabolomics and culturomics; ii) self-collection device that would allows the collection of faecal material and the generation of aliquots for all possible omic assessments for research purposes, including metagenomic analysis, as well as culturomics and faecal transfer to animal models.

Inclusion Criteria:

• Male and/or female
• Age between 18 and 85 years
• No diagnosed pathology
• Not opposed to following the study procedures

Exclusion Criteria:

• Ongoing digestive neoplasia or < 5 years
• Digestive surgery with intestinal resection
• Presence of inflammatory bowel disease or other familial gastrointestinal pathology
• Chronic use of laxatives
• Use of antibiotics in the two months prior to inclusion
• Life-threatening conditions in the short term (progressive cancer, unstable heart failure, severe liver, kidney or respiratory failure)
• Chronic psychosis or psychotic episodes
• Alcohol or drug addiction
• Epilepsy and other non-degenerative diseases of the central nervous system
• Vitamin B12 and folic acid deficiency not supplemented
• Untreated hypothyroidism
• Pregnant or breastfeeding woman
• Person deprived of liberty by judicial or administrative decision
• Major protected by law
• Not affiliated with a social security scheme or beneficiary of such a scheme
• Having a period of relative exclusion in relation to another protocol
• Having refused to participate in the protocol