Mediation of the microbiome-gut axis by oyster (Crassostrea gigas) polysaccharides: A possible protective role in alcoholic liver injury

The objective of this study was to evaluate the molecular mechanism by which polysaccharides from Crassostrea gigas (RPS) prevent alcoholic liver injury and to uncover whether the steaming process affects the bioactivities of RPS. Oral administration of RPS or polysaccharides from steamed oyster (SPS) (282 mg/kg b.w.) significantly attenuated alcoholic liver injury in mice. RPS and SPS treatments protected gut functions by significantly enhancing the expression of tight-junction proteins and suppressing inflammatory responses. RPS and SPS treatments also significantly increased Lactobacillus reuteri and Roseburia spp. and decreased the level of Escherichia. Microbial metabolites, especially propionate and butyrate, were also increased in RPS- and SPS-treated mice. Correlation analysis revealed that the beneficial effects of RPS and SPS were strongly correlated with the microbiota composition and SCFAs. These results indicated that oyster polysaccharides alleviated alcoholic liver injury by mediating the gut-liver-metabolite axis, and the steaming process had little influence on the bioactivity.