Microbial metabolism of (+)-catechin, (-)-epicatechin and proanthocyanidins by human fecal microbiota in vitro

The aim of the study was to investigate in vitro microbial metabolism of flavan-3-ols [(+)-catechin, (-)-epicatechin, proanthocyanidins (PA)] from different plant sources using human fecal microbiota as an inoculum to identify the main degradation products of flavan-3-ols. Microbial transformations varied depending on the source and structure of the flavan-3-ols with clear differences in time-extent profiles for each substrate. Whereas (+)-catechin gave rise to 3,4-dihydroxyphenylpropionic acid as a primary product, the stereoisomer (-)-epicatechin, surprisingly, did not