Mulberry leaf-derived polysaccharide modulates the immune response and gut microbiota composition in immunosuppressed mice

Mulberry leaf polysaccharide (MLP) possess many biological characteristics, such as immunomodulatory and antioxidant properties, but whether MLP can impact the distribution and characteristics of the gut microbiota is not yet clear. In this study, the effects of MLP on diversity- and immune-related factors and short-chain fatty acids (SCFAs) of the gut microbiota in mice were investigated. The results showed that MLP could restore the indexes of the thymus and spleen, the damaged intestinal barrier and levels of inflammatory cytokines in cyclophosphamide (CTX)-treated mice, and alleviate oxidative damage to the liver. Additionally, MLP were associated with a relatively higher abundance of Bacteroidetes but lower levels of Firmicutes, Butyricimonas and Eubacterium in CTX-treated mice. Moreover, MLP restored the levels of acetic acid, propionic acid, and n-butyric acid reduced by CTX. These results indicated that MLP, as a special ingredient, might regulate the immune response by altering the spatial structure of the gut microbiota and the production of SCFAs.