Apple Cider Vinegar Powder Mitigates Liver Injury in High-Fat-Diet Mice via Gut Microbiota and Metabolome Remodeling

<b>Background/Objectives</b>: High-fat-diet (HFD) consumption drives chronic liver injury via gut dysbiosis and metabolic disturban. Apple cider vinegar, rich in polyphenols and organic acids, shows potential in metabolic regulation. This study aimed to investigate whether apple cider vinegar powder (ACVP) alleviates HFD-induced liver injury by modulating the gut-liver axis. <b>Methods</b>: For 12 weeks, C57BL/6 J mice received daily ACVP gavage while being fed a HFD. A series of biological assessments were conducted, including systemic metabolic evaluations (body weight, serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), and lipid/glucose levels), hepatic steatosis (hematoxylin and eosin (H&E) staining), intestinal microbiome characterization (16S rRNA gene genomic analysis), and comprehensive metabolite profiling of cecal contents (non-targeted metabolomics). Pearson correlation networks integrated multi-omics data. <b>Results</b>: ACVP attenuated HFD-induced weight gain by 26.3%, hepatomegaly and dyslipidemia, as well as reduced hepatic lipid vacuoles and serum ALT (48%)/AST (21.5%). ACVP restored gut microbiota diversity, enriching <i>Muribaculaceae</i>. Cecal metabolomics identified 38 HFD-perturbed metabolites reversed by ACVP, including indolelactate, hyocholate, and taurocholic acid. the Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed ACVP-mediated recovery of linoleic acid metabolism. Correlation networks linked <i>Akkermansia</i> to anti-inflammatory metabolites (e.g., trans-ferulic), while Desulfobacterota correlated with pro-inflammatory oxylipins (e.g., 12,13-dihydroxy-9Z-octadecenoic acid (DHOME)). <b>Conclusions</b>: ACVP mitigates HFD-induced liver injury by remodeling gut microbiota, restoring microbial metabolites, and enhancing gut-liver crosstalk.