Effects of cadmium on organ function, gut microbiota and its metabolomics profile in adolescent rats

Cadmium (Cd) exposure in adult animals can result in multi-organ damages and gut microbiota disturbance. However, Cd's consequences on health and gut microbiota during adolescence are obscure. In the present study, three-week-old SD rats were exposed to Cd at doses of 0, 0.25, 1, and 4 mg/kg body weight for eight weeks, and the changes of liver, kidney, and ovary function, as well as gut microbiota and its metabolomics profile, were analyzed. After transplantation of fecal bacteria from the 4 mg/kg Cd-treated group into age-matched rats (4 mg/kg-Cd recipients), the organ function and inflammatory reaction were evaluated. The results indicated that Cd perturbed gut microbiota composition, significantly decreased the abundance of Prevotella and Lachnoclostridium but increased Escherichia coli_Shigella. The fecal metabolome profile was altered and was closely correlated with some specific genera. These changes were accompanied by the inflammatory response, dyslipidemia, kidney dysfunction, and abnormal estrogen level. In 4 mg/kg-Cd recipients, the serum triglyceride (TG), lipopolysaccharide (LPS), and inflammatory cytokines were increased with the expressions of IL-1β, IL-6, TNF-α genes up-regulated in liver and kidney. Overall, this study demonstrated that Cd exposure during adolescence could cause disturbance of gut microbiota, dysfunction of liver, kidney, and ovary, which may be correlated with the activation of Cd-induced inflammatory response.