In vitro simulated digestion and fermentation behaviors of polysaccharides from Pleurotus cornucopiae and their impact on the gut microbiota

Abstract

This study investigated the physicochemical characteristics and fermentative behavior between original polysaccharides (PCPs) and polysaccharides extracted after microwave cooking (MPCPs) from Pleurotus cornucopiae during simulated digestion and fecal fermentation. The results revealed notable physicochemical differences between of PCPs and MPCPs. MPCPs exhibited a higher total carbohydrate content, with an increased proportion of glucose. Additionally, MPCPs showed a lower molecular weight (MW) and, a blue shift in Fourier transform infrared spectroscopy (FT-IR). Digestion has a minimal effect on the physicochemical and structural characteristics of PCPs and MPCPs. Within the first 6 h of fermentation, the gut microbiota showed significantly higher utilization of MPCPs. However, PCPs were consumed faster and surpassed MPCPs later. After 24 h, both PCPs and MPCPs were degraded and utilized by the gut microbiota, showing an increased abundance of Firmicutes and Bacteroidota. PCPs excelled in promoting beneficial gut microbiota, such as Phascolarctobacterium, Megamonas, and Bacteroides. Conversely, MPCPs demonstrated a stronger ability to inhibit the growth of harmful opportunistic pathogenic gut microbiota, such as Fusobacterium and Parasutterella. In addition, the content of acetic, propionic, and butyric acids increased significantly in both PCPs and MPCPs. These findings highlight the potential of Pleurotus cornucopiae polysaccharides as prebiotics for intestinal homeostasis.