To design and understand the mechanism of action of different combinations of nutraceuticals coupling bacteria, fibers and polyphenols, which can act on the 4 pillars simultaneously via an innovative ex-vivo model approach coupled with functional and quantitative metagenomics.

The objective of the study is to collect fresh stools from 4 healthy volunteers, in order to study the mechanism of action of probiotic strains, polyphenols and fibers, alone or in combinations. These fresh stools will be cultured in vitro in fermenters, and the samples taken at different culture times will be analyzed in terms of microbial composition (shotgun metagenomic analysis) and their cellular activity (functional metagenomic analysis).

Inclusion Criteria:

• Person with a low fiber diet (<17g / day).

Exclusion Criteria:

• Taking antibiotics and / or transit modulators in the 3 months preceding the sample;
• Colonoscopy in the last 3 months;
• Person under legal protection measure (curators, tutors, etc.).

The research will be carried out on 4 healthy volunteers. The research will be carried out by the coordinating team of the INRAE MetaGenoPolis Unit.