title: Reply to C Matuchansky.
authors.affiliation: INRA UMR1319 Micalis Jouy-en-Josas, 78350 France E-mail: joel.dore@jouy.inra.fr.
authors.forename: Joël
authors.initials: J
authors.lastname: Doré
authors.forename: Karine
authors.initials: K
authors.lastname: Clément
mesh_terms: D052436:Adipose Tissue, White / Q000378:metabolism*; D005260:Female; D015390:Gastric Bypass / Q000379:methods*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D054892:Metagenome; D009767:Obesity, Morbid / Q000382:microbiology*