Taurocholic acid metabolism by gut microbes and colon cancer.
Colorectal cancer (CRC) is one of the most frequent causes of cancer death worldwide and is associated with adoption of a diet high in animal protein and saturated fat. Saturated fat induces increased bile secretion into the intestine. Increased bile secretion selects for populations of gut microbes capable of altering the bile acid pool, generating tumor-promoting secondary bile acids such as deoxycholic acid and lithocholic acid. Epidemiological evidence suggests CRC is associated with increased levels of DCA in serum, bile, and stool. Mechanisms by which secondary bile acids promote CRC are explored. Furthermore, in humans bile acid conjugation can vary by diet. Vegetarian diets favor glycine conjugation while diets high in animal protein favor taurine conjugation. Metabolism of taurine conjugated bile acids by gut microbes generates hydrogen sulfide, a genotoxic compound. Thus, taurocholic acid has the potential to stimulate intestinal bacteria capable of converting taurine and cholic acid to hydrogen sulfide and deoxycholic acid, a genotoxin and tumor-promoter, respectively.
['Ridlon|Jason M|JM|', 'Wolf|Patricia G|PG|', 'Gaskins|H Rex|HR|']
D001646:Bile D002756:Cholagogues and Choleretics D003110:Colonic Neoplasms D003840:Deoxycholic Acid D003902:Detergents D000069196:Gastrointestinal Microbiome D041981:Gastrointestinal Tract D006801:Humans D006862:Hydrogen Sulfide D009153:Mutagens D013656:Taurocholic Acid
colon cancer diet bile acid deoxycholic acid taurine hydrogen sulfide