Sea Cucumber Polysaccharides Promote Gut–Liver Axis Health by Modulating Microbiota, Metabolism, and Gene Expression in Mice

This study investigated the beneficial effect of sea cucumber polysaccharides (SCP) on gut microbiota composition, metabolic profiles, and liver gene expression in mice. Using an integrative approach combining microbiome, metabolome, and transcriptome analyses, we demonstrated that SCP supplementation led to a marked rise in norank_f_Muribaculaceae levels and reduced the Firmicutes-to-Bacteroidota ratio. Metabolomic analysis revealed key alterations in amino acid and lipid metabolism, with L-arginine and 7-dehydrocholesterol identified as potential mediators of SCP’s beneficial effects. Transcriptomics revealed genes expression across nine metabolic pathways, with genes involved in steroid biosynthesis being upregulated, while those related to protein digestion and absorption were downregulated. Spearman’s correlation analysis highlighted strong associations between gut microbiota, lipid metabolism-related genes, and corresponding metabolites. Integration omics data further suggested that SCP primarily supports arginine biosynthesis through gut–liver axis crosstalk. These results provide an important basis for developing SCP-based functional food with prebiotic properties to support metabolic and liver health.