Integrated Multi-Omics Reveals Synergistic Hepatotoxicity of Ethanol and PFOS Co-Exposure.

Alcohol-associated liver disease (ALD) and exposure to per- and polyfluoroalkyl substances (PFAS) share key mechanisms of hepatotoxicity, yet their combined effects remain poorly characterized. We evaluated the impact of concurrent ethanol and perfluorooctanesulfonic acid (PFOS) exposure using a murine Lieber-DeCarli model characterized via multi-omic, spatial lipidomic, and metagenomic analyses. Exposure to PFOS resulted in rapid weight loss, while co-exposure led to decreased survival and pronounced hepatomegaly exceeding the effects of either exposure alone despite reduced cumulative ethanol intake. Histological analysis revealed enhanced hepatocellular injury with combined macrovesicular and microvesicular steatosis, consistent with impaired lipid handling and mitochondrial dysfunction. Transcriptomic and metabolomic profiling demonstrated disruption of xenobiotic metabolism, fatty acid β-oxidation, mitochondrial function, and bile acid transport, with PFOS acting as a dominant driver of metabolic stress and ethanol amplifying injury-related responses. Spatial lipidomics revealed hepatocyte-scale remodeling of membrane phospholipids, characterized by increased phosphatidic acid and depletion of phosphatidylinositol and phosphatidylserine under PFOS-containing conditions. Plasma metabolomics indicated systemic metabolic disturbance, including altered amino acid and redox pathways and depletion of microbiome-derived indole metabolites. Metagenomic analysis revealed reduced bacterial load and severe dysbiosis characterized by loss of commensal anaerobes, expansion of opportunistic taxa, and decreased microbial biosynthetic capacity. These findings indicate that PFOS increases susceptibility to alcohol-induced liver injury potentially through coordinated disruption of hepatic metabolism and gut-liver crosstalk, highlighting environmental PFAS exposure as a potential modifier of ALD severity.