INS and hepatocellular carcinoma: To explore the effects of phytosphingosine produced by F. plautii on metabolic disorders in vitro, an insulin-resistant human hepatocellular carcinoma (HepG2) cell model and a fatty HepG2 cell model were generated and treated with two doses of phytosphingosine, which were selected based on CCK-8 test results (Supplementary Fig. S20).