Schizophyllum commune-derived beta-glucan improves intestinal health demonstrating protective effects against constipation and common metabolic disorders

Abstract

It has been proven that beta-glucan produced by Schizophyllum commune has beneficial effects on obesity, obesity-associated constipation, and colitis conditions; however, the protective effect of the compound on host at basal state is yet to be investigated. C57BL/6 J mice were fed with a normal diet (ND), normal diet supplemented with 3 g/kg (BG_low), and 5 g/kg (BG_high) of beta-glucan (BG) for 12 weeks. Body weight, food and water intake and fecal status were monitored weekly. Intestine was stained by Periodic acid-Schiff (PAS) and Alcian Blue to evaluate the mucin layer thickness and goblet cell population. Morphological changes in internal organs and intestinal motility were also assessed, while serum biomarkers for liver injury and glucose level were analyzed. On the other hand, fecal microbiota and associated metabolic activities were also investigated. beta-glucan bulked feces, decreased fecal moisture, and proliferated goblet cells resulted in a thickened lubricating mucin layer; however, the intestinal transit rate did not increase. The abundance of beneficial bacteria was increased while the harmful strains was decreased in a dose-dependent manner by the effect of beta-glucan. Specific short chain fatty acid (SCFA)-producing strains, such as Roseburia, Ruminococcus, and Bifidobacteria, were selectively increased by beta-glucan. In addition, consumption of beta-glucan lowered level of obesity-associated biomarkers. Schizophyllum commune beta-glucan showed an insignificant change in transit rate in healthy conditions when compared with obesity, despite similar effects on increasing mucus production and bulked feces. Nonetheless, the outcomes proposed protective effects against obesity, diabetes, inflammatory bowel diseases (IBD), and constipation, in which the modification of the gut microbiota by beta-glucan is the largest contributor.