Bioconversion of (−)-epicatechin (−EC), (+)-epicatechin (+EC), (−)-catechin (−C), and (+)-catechin (+C) by (−)-epigallocatechin (−EGC)-metabolizing bacteria, Adlercreutzia equolifaciens MT4s-5, Eggerthella lenta JCM 9979, and Flavonifractor plautii MT42, was investigated. A. equolifaciens MT4s-5 could catalyze C ring cleavage to form (2 S )-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol ( 1S ) from −EC and −C, and (2 R )-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol ( 1R ) from +C. The C ring cleavage by A. equolifaciens MT4s-5 was accelerated in the presence of hydrogen. E. lenta JCM 9979 also catalyzed C ring cleavage of −EC and +C to produce 1S and 1R , respectively. In the presence of hydrogen or formate, strain JCM 9979 showed not only stimulation of C ring cleavage but also subsequent 4′-dehydroxylation of 1S and 1R to produce (2 S )-1-(3-hydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol ( 2S ) and (2 R )-1-(3-hydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol ( 2R ), respectively. On the other hand, A. equolifaciens MT4s-5 did not show any 4′-dehydroxylation ability even in the presence of hydrogen. F. plautii MT42 could convert 1S , 1R , 2S , and 2R into their corresponding 4-hydroxy-5-hydroxyphenylvaleric acids and 5-hydroxyphenyl-γ-valerolactones simultaneously. Similar bioconversion was observed by F. plautii ATCC 29863 and F. plautii ATCC 49531.