Steam-exploded Dictyophora indusiata polysaccharide regulated gut microbiota based on dynamic in vitro stomach-intestine digestion system

Dictyophora indusiata is a nutritious edible mushroom, which polysaccharide exhibited a variety of biological activities. In this study, the digestion properties of steam-exploded Dictyophora indusiata polysaccharide (DIPS) were investigated by dynamic in vitro stomach-intestine digestive system. Here, the molecular weight of DIPS significantly was decreased and the microscopic surface structure appeared to be loose after 90 min of simulated stomach digestion. Interestingly, the molecular weight of DIPS was restored during the small intestine digestion phase, which was not significantly different compare with DIPS before stomach digestion, the functional groups, thermal stability and antioxidant properties of DIPS remained stable after digestion. It is remarkable that DIPS after dynamic in vitro stomach-intestine digestion regulated the composition of the gut microbiota, including Blautia , Megamonas , Parabacteroides and Phascolarctobacterium . In addition, DIPS promoted the level of acetic acid, propionic acid and butyric acid during the in vitro fermention, which were 2.42, 4.36 and 9.17 folds higher than controls, respectively. This study provides important significance for exploring the effects of edible mushroom polysaccharide on gut health.