tauromuricholate

Tauromuricholate is the taurine conjugate of muricholic acid, a primary bile acid found predominantly in rodents. Muricholic acids, including alpha- and beta-muricholic acids, are C24 bile acids produced in the liver and incorporated into the biliary bile acid pool in mice and rats. Taurine conjugation, carried out by the enzyme bile acid-CoA:amino acid N-acyltransferase, attaches taurine to muricholic acid to form tauromuricholate, which is then secreted into bile.

As a conjugated bile acid, tauromuricholate is more water-soluble than the free muricholic acids, aiding the emulsification of dietary fats and supporting enterohepatic circulation. The muricholic family tends to be relatively hydrophilic compared with some other bile acids, which influences the overall bile acid pool and microbial transformations in the gut.

Occurrence of tauromuricholate is particularly notable in mice and some other rodents, where it can be a major component of biliary and intestinal bile acids. In humans, muricholic acids occur only at trace levels, and tauromuricholate is not a common endogenous metabolite.

Metabolism and microbiology considerations include deconjugation by intestinal bacteria and transformation into secondary bile acids. The relative abundance of tauromuricholate is influenced by diet, genetics, and the composition of the gut microbiota.

In research contexts, tauromuricholate is used to study rodent bile acid metabolism, liver function, and host–microbiome interactions, and it helps illustrate species differences in bile acid composition.