[ODP-084] Development of a qRT-PCR method of fecal bacteria responsible for transformation of bile acids
Secondary bile acids have wide-ranging effects on host health. Deoxycholic acid and lithocholic acid are the main components of the bile acid profile of stool in healthy humans and have been associated causally with diseases of the gastrointestinal tract. On the other hand, numerous studies described their antimicrobial effects highlighting their ability to provide colonization resistance against Clostridium difficile. Therefore, evaluation of the distribution of bacteria responsible for 7α-dehydroxylation is important in understanding diseases in the gastrointestinal tract.Enzymes involved in 7α-dehydroxylation are encoded by bile acid-inducible (bai) genes. It is known that the bai gene cluster is present and expressed in most individuals, and its main representatives are uncultivated members. Yet, there is little information on which bacteria in the human gut makes a major contribution on bile acid transformation since only small portion of intestinal bacteria can perform this reaction.In this study, we are sought to quantify predominant intestinal bacteria producing the secondary bile acid in human gut. Shotgun metagenomics were used to explore predominant intestinal bacteria. Based on these information, we developed a quantitative real-time PCR method for the predominant bacteria exhibiting baiCD gene and quantified them in human fecal samples.