The fermentation characteristics of Sparassis crispa polysaccharides and their effects on the intestinal microbes in mice

Sparassis crispa polysaccharides (SCPs) have multiple pharmacological activities. Fermentation characteristics of SCPs and its effects on the intestinal microbes in mice remain inconclusive. In this study, SCPs were fermented by the human feces and used to administer the Kunming mice to explore the fermentation characteristics of SCPs in the intestinal tract and the effects on the intestinal microbes in mice. Results from in vitro experiments revealed that SCPs were utilized by intestinal microbiota to produce short-chain fatty acids (SCFAs). The specific monosaccharide composition of SCPs determines which SCFAs are produced. Furthermore, the colon index and villi length of the SCPs-treated mice were significantly higher compared with the control group. In addition, SCPs exhibited beneficial effect on the relative abundance and diversity of dominant bacteria in the intestinal tract, such as increasing Bacteroidetes/Firmicutes ratio and up-regulating SCFA-producing bacteria, including Bacteroidales_S24-7_group, Alloprevotella, Alistipes, Bacteroides, Butyricimonas, Parabacteroides, Lachnospiraceae_NK4A136_group and Oscillibacter. SCPs increased the abundance of genes in carbohydrate, amino acid, and energy metabolism. Our results indicate SCPs can improve the physiological indices of the colon in mice, which is likely to be associated with the increase in the relative abundance and diversity of SCFA-producing bacteria and SCFAs level produced by intestinal microbiota.