Effects of Schisandra chinensis polysaccharides on rats with antibiotic-associated diarrhea

Schisandra chinensis (S. chinensis), a traditional Chinese medicine (TCM), is comprised of polysaccharides as its main active component. In this study, water-soluble polysaccharides from S. chinensis (WSP) were extracted, and their effects on rats with antibiotic-associated diarrhea were investigated. The rats were treated with lincomycin hydrochloride, followed by saline (natural recovery [NR] group) or WSP (WSP group). The body weight and water intake of rats were analyzed, as well as histological data. Other experiments involving a measurement of cytokine levels, 16s rRNA sequencing analysis of caecal contents, and a measurement of the concentration of short chain fatty acids (SCFAs) were also performed. Compared to rats of the NR group, WSP decreased the infiltration of inflammatory cells into the ileum and colon; decreased the levels of IL-4, IL-17A and TNF-α; increased the serum IL-2 and IL-10 levels; increased the relative abundance of Blautia, Intestinibacter and Lachnospiraceae-UCG-008, but decreased the relative abundance of Ruminococcus-1, Ruminococcaceae-UCG-014 and Erysipelatoclostridium at the genus level; and significantly increased the contents of total SCFAs, acetate and propionate. In conclusion, WSP affected rats with antibiotic-associated diarrhea by improving the ultrastructure of the gut, adjusting cytokine levels and modifying the gut microbial community and SCFAs production.