Fungicide Chlorothalonil Exposure Induced Intestinal Impairment via the Microbiota/Sphinganine/Ferroptosis Axis.

Chlorothalonil is linked to gastrointestinal toxicity, but its underlying mechanisms remain unclear. This study investigated the chlorothalonil-induced intestinal injury in mice. Histological analysis showed epithelial damage and goblet cell depletion. Chlorothalonil disrupted the gut microbiota, including the depletion of Lactobacillus and the enrichment of Enterococcus. Untargeted metabolomics revealed a reduction in sphinganine, which is associated with oxidative stress and ferroptosis. Molecular analysis indicated ferroptosis activation via the Keap1/Nrf2 pathway, evidenced by decreased glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression. Prussian blue staining and transmission electron microscopy confirmed iron deposition and mitochondrial injury, hallmark features of ferroptosis. Fecal microbiota transplantation confirmed dysbiosis as a driver of injury, while ferrostatin-1 treatment partially rescued the pathological phenotype. These findings demonstrate that chlorothalonil causes microbiota dysbiosis and decreases sphinganine, which inactivates Nrf2 signaling and results in ferroptosis. Our study provides new mechanistic insights into the toxicological mechanisms of chlorothalonil.