Gastrointestinal digestion, probiotic fermentation behaviors and immunomodulatory effects of polysaccharides from Sanghuangporus vaninii

In this study, the crude polysaccharides (CSVP) and the preliminary purified polysaccharides (PSVP) from Sanghuangporus vaninii were obtained. The physicochemical properties, gastrointestinal digestion, and probiotic fermentation behaviors of CSVP and PSVP as well as the immunomodulatory effects of PSVP in cyclophosphamide-treated mice were investigated. The results showed that PSVP had higher total polysaccharides content and solubility, but lower radical scavenging activity than CSVP. Moreover, PSVP showed lower hydrolysis degree and better probiotic effects than CSVP. In immunosuppression mice model, PSVP supplement increased the body weight, spleen and thymus index, improved the release of cytokines IFN-γ, immunoglobulins IgM and IgG, and enhanced the lysozyme activity. Moreover, PSVP supplement significantly prevented the oxidative stress in vivo, increased the level of beneficial gut microbiota, especially Bacteroidaceae and Lactobscillsceae, as well as the content of short-chain fatty acids (SCFAs). These results indicated that PSVP could recover the immune response in cyclophosphamide-treated mice by regulating gut microbiota and intestinal barrier. The findings will lay a theoretical foundation for equitable utilization of S. vaninii resources as well as the product development.