Comprehensive assessment of Hypsizygus marmoreus polysaccharides through simulated digestion and gut microbiota fermentation in vitro

Edible mushroom polysaccharides have attracted increasing attention recently due to their health-promiting biofunctions. Herein, we isolated and characterized polysaccharides from H. marmoreus (HMP). The gastrointestinal digestion and colon fermentation characteristics of HMP and its effects on gut microbe were investigated by a simulated digestion and fermentation model in vitro. We found no significant difference in molecular weight, monosaccharide composition, and total or reducing sugar content of HMP after the simulated digestion, suggesting that HMP was indigestible and could reach the colon. After colonic fermentation, HMP was degraded by gut microbiota, producing short-chain fatty acids, especially acetate and propionate, which in turn reduced the pH value. Simultaneously, HMP regulated the gut microbiota. A decrease in the abundance of Fusobacterium and Desulfovibrio, as well as an increase in the abundance of Prevotella and Faecalibacterium in HMP group were observed. In summary, HMP could be considered a potential prebiotic candidate.