Chlorpyrifos disturbs hepatic metabolism associated with oxidative stress and gut microbiota dysbiosis in adult zebrafish.

Chlorpyrifos (CPF) is widely used in agriculture and is considered one of the most toxic pesticides to fish. In this study, adult male zebrafish were exposed to CPF at concentrations of 30, 100 and 300 μg/L for 21 days. It was observed that CPF not only induced oxidative stress but also caused gut microbiota dysbiosis in the gut. The malondialdehyde (MDA) levels increased, and the glutathione (GSH) contents decreased in the gut of the CPF-treated group. For the gut microbiota, at the phylum level, the relative abundance of Proteobacteria showed a significant change after CPF exposure. At the genus level, approximately 25 types of bacteria in the gut changed significantly. In addition, based on a gas chromatography combined with mass spectrometry (GC/MS) analysis, we found that 98 metabolites significantly influenced the zebrafish liver, and these changed metabolites were tightly related to several pathways, including glucose and lipid metabolism, the tricarboxylic acid (TCA) cycle, and amino acid metabolism. Furthermore, the transcriptional levels of some genes related to glycolysis and lipid metabolism decreased significantly in the livers of CPF-treated zebrafish. These results indicated that CPF exposure could induce hepatic glucose and lipid metabolism disorders in adult zebrafish. Taken together, our results suggest that CPF exposure causes hepatic lipid metabolism disorders that are associated with gut oxidative stress and microbiota dysbiosis in adult zebrafish.