Digestion characteristics in vitro of polysaccharide from Pleurotus placentodes and its positive effects on microbiota

Pleurotus placentodes , a nutritionally rich mushroom species within the Pleurotus spp. genus, contains rich polysaccharides. As its primary bioactive component, it has been rarely reported. This study provided the first report on in vitro digestion and fermentation properties of polysaccharide PPp-W through simulated digestion and anaerobic fermentation. The results showed that during simulated digestion, PPp-W resisted enzymatic degradation, as shown by its stable molecular weight and absence of free monosaccharide release. However, PPp-W was degraded and utilized by intestinal microorganisms, leading to the production of short-chain fatty acids (SCFAs), particularly acetic acid (increased 2.61 times) and propionic acid (increased 19.79 times), accompanied by a marked pH reduction in fecal culture medium. PPp-W administration significantly regulated the composition of intestinal flora by enhancing the relative abundance of beneficial bacteria ( Bacteroides , Parabacteroides , and Lactobacillus ) while suppressing harmful bacteria ( Escherichia - Shigella and Enterococcus ). These findings indicated that PPp-W exhibited significant prebiotic potential and represented a promising candidate for functional food applications targeting gut health modulation.