In vitro and in vivo characterization of Clostridium scindens bile acid transformations.

摘要: The human gut hosts trillions of microorganisms that exert a profound influence on biology. Gut bacteria communicate with their host by secreting small molecules can signal to distant organs in the body. Bile acids are one class these signaling molecules, synthesized and chemically transformed microbiota. Among bile acid metabolizers, 7-dehydroxylating commensals particular importance as they carry out 7-dehydroxylation liver-derived primary 7-dehydroxylated acids. latter represents major fraction secondary pool. microbiology this group is understudied warrants more attention. Here, we detail transformations carried bacterium Clostridium scindens vitro vivo. In vitro, C. exhibits not only 7α-dehydroxylating capabilities but also, ability oxidize other hydroxyl groups reduce ketone This study revealed 12-oxolithocholic transient product 7α-dehydroxylation cholic acid. Furthermore, vivo included complementing gnotobiotic mouse line (devoid 7-dehydroxylate acids) investigating its colonization dynamics transformations. Using NanoSIMS (Nanoscale Secondary Ion Mass Spectrometry), demonstrate large intestine constitutes niche for scindens, where it efficiently 7-dehydroxylates deoxycholic Overall, work reveals novel species during well provides direct evidence growth intestine.