In vitro prebiotic function of oligosaccharides from Schizophyllum commune and its sulfated derivatives

Abstract

Beta-1,3-glucans have been identified as effective prebiotics. However, their high molecular weight and low water solubility often limit their utilization efficiency by intestinal microbes. In this study, we aimed to address this issue by performing co-culture of Schizophyllum commune and Trichoderma harzianum to produce S. commune oligosaccharide (ScOG) with branched chain structures. Additionally, we obtained its sulfated derivatives (S-ScOG) through the sulfur trioxide-pyridine method and the sulfated curdlan oligosaccharides (S-COS) was used as control. Our findings indicate that both ScOG and S-ScOG demonstrated strong resistance to digestion by saliva, gastric juice, and small intestinal fluid. Moreover, S-COS and S-ScOG exhibited superior scavenging ability for DPPH and hydroxyl radicals. In vitro fermentation of ScOG and its derivatives with healthy human fecal microbiota showed that ScOG increased the abundance of Lactobacillus, while S-ScOG enriched the populations of Bacteroides and butyric acid-producing bacteria compared to the blank group. Notably, S-COS and S-ScOG increased the abundance of Bifidobacteria, and S-ScOG was particularly effective in maintaining microbial community diversity. Furthermore, both S-COS and S-ScOG were easily utilized by intestinal microbiota and significantly enhanced the production of short-chain fatty acids. Overall, ScOG has good prebiotic potential and that sulfation modification can effectively enhance its prebiotic effects.