Maternal exposure to tris (2-chloroethyl) phosphate during pregnancy and suckling period alters gut microbiota and SCFAs metabolism in offspring of rats.

Tris(2-chloroethyl) phosphate (TCEP), one of the most widely used organophosphate flame retardants, is frequently detected in environmental and biological samples. However, its toxic effects on the offspring remain unknown. To explore the health risks posed by TCEP in susceptible populations, we investigated the intergenerational transmission of TCEP, gut microbiome, and disruptive effects of intestinal metabolites in the offspring. Different doses of TCEP were administered orally to female Sprague-Dawley (SD) rats throughout pregnancy or during both pregnancy and lactation periods. Concentrations of TCEP and its metabolite, BCEP, composition of the gut microbiota, and fecal concentrations of short-chain fatty acids were measured. The concentration of TCEP in the placenta of rats in the high-dose group was significantly higher than that in the control group, and BCEP was also present. Serum and fecal samples from immature offspring contained TCEP; however, no BCEP was detected in serum. Exposure to TCEP altered the intestinal microbiota of both the maternal rats and their offspring. The relative abundance of Coelenterata was significantly increased in the immature offspring. Exposure to TCEP altered the concentration of SCFAs in the feces of the rats and their offspring. Lower concentrations of acetic, propionic, and butyric acids were observed in the feces of immature offspring. Holdemanella had a significant mediating effect between TCEP exposure and intestinal concentrations of acetic and propionic acids. Maternal exposure to TCEP affects the gut microbiota balance and metabolism of offspring, suggesting the presence of a long-term risk associated with metabolic disease.