Perinatal Triclosan exposure in the rat induces long-term disturbances in metabolism and gut microbiota in adulthood and old age

Triclosan (TCS), as a widely used antimicrobial compound, is commonly detected in pregnant women and newborns indicating exposure risk during early development. However, whether perinatal TCS exposure has long-term effects on the host microbiome which further contributes to metabolic disorder is still unclear. The long-term effects of perinatal TCS exposure on gut microbiota and liver metabolism in adulthood and old age were investigated. Rats were given 0, 10 or 50 mg TCS/kg body weight per day, administered daily by gavage from gestation day 0 until lactation day 21. RNA-sequencing and 16 S rDNA amplicon sequencing analysis were performed to explore the potential mechanisms. Increased blood glucose and serum HDL-C were observed at 10 mg/kg/day in old rats and at 50 mg/kg/day in both adult and old rats. Serum leptin were increased at two doses in old rats. Serum TG and LDL-C were increased at two doses in both adult and old rats. Hepatic glycogen were decreased at 50 mg/kg/day in adult rats and at two doses in old rats. Increased hepatic TG were observed at two doses in old rats. Hepatic RNA-sequencing revealed that more differentially expressed genes were found at 50 mg/kg/day in both adult and old rats. More up-regulated genes in pathways of carbohydrate and lipid metabolism were observed in old rats at 50 mg/kg/day. Diversity reduction and compositional alteration were found in gut microbiota at 50 mg/kg/day in adult rats and at two doses in old rats. These effects lasted for a long time even without TCS exposure and accumulated over time inducing metabolic disorder in old rat offspring. TCS exposure during early life causes disturbances in metabolism and gut microbiota which last a lifetime and accumulated over time at 50 mg/kg/day. Further research is needed to investigate the effects of early life TCS exposure on metabolism and gut microbiota in humans.