Metabolic fate of environmental chemical triclocarban in colon tissues: roles of gut microbiota involved.

Metabolic transformations play critical roles in the bioavailability and toxicities of environmental pollutants and toxicants. However, most previous research has focused on the metabolic reactions in host tissues, the gut microbiota-mediated biotransformation of environmental compounds is understudied. Using triclocarban (TCC) as a model environmental compound, here we study the metabolic fate of TCC in gut tissues and determine the roles of gut microbiota involved. We find that compared with other tissues, the colon tissue has a unique metabolic profile of TCC, with high abundance of the parent compound TCC and its free-form metabolites. Using a variety of approaches including antibiotic-mediated suppression of gut bacteria in vivo, germ-free mice, and in vitro culture of fecal bacteria, we found that the unique metabolic profile of TCC in the colon is mediated by the actions of gut microbiota. Overall, our findings support that gut microbiota plays important roles in colonic metabolism of TCC, highlighting the importance to consider the contributions of gut microbiota in toxicology evaluation of environmental compounds.