Chronic exposure to low concentrations of lead induces metabolic disorder and dysbiosis of the gut microbiota in mice

Lead (Pb) is one of the most prevalent toxic, nonessential heavy metals that can contaminate food and water. In this study, effects of chronic exposure to low concentrations of Pb on metabolism and gut microbiota were evaluated in mice. It was observed that exposure of mice to 0.1 mg/L Pb, supplied via drinking water, for 15 weeks increased hepatic TG and TCH levels. The levels of some key genes related to lipid metabolism in the liver increased significantly in Pb-treated mice. For the gut microbiota, at the phylum level, the relative abundance of Firmicutes and Bacteroidetes changed obviously in the feces and the cecal contents of mice exposed to 0.1 mg/L Pb for 15 weeks. In addition, 16 s rRNA gene sequencing further discovered that Pb exposure affected the structure and richness of the gut microbiota. Moreover, a 1H NMR metabolic analysis unambiguously identified 31 metabolites, and 15 metabolites were noticeably altered in 0.1 mg/L Pb-treated mice. Taken together, the data indicate that chronic Pb exposure induces dysbiosis of the gut microbiota and metabolic disorder in mice. Chronic Pb exposure induces metabolic disorder, dysbiosis of the gut microbiota and hepatic lipid metabolism disorder in mice.