Regulatory effect of non-starch polysaccharides from purple sweet potato on intestinal microbiota of mice with antibiotic-associated diarrhea.

Antibiotic treatment causes antibiotic-associated diarrhea (AAD), which is usually accompanied by disorders of the intestinal flora, aggravating the patient's condition. Recently, more attention has been devoted to the ability of plant polysaccharides to improve the body's flora and enhance immunity. However, reports on whether purple sweet potato polysaccharides (PSPPs) can improve AAD are scarce. This study aimed to extract a non-starch polysaccharide from purple sweet potato and analyze its structure and ability to regulate the intestinal flora of mice with AAD. The diarrhea model was established via intragastric administration of lincomycin and different concentrations of PSPPs (0.1 g kg-1, 0.2 g kg-1, and 0.4 g kg-1) to Balb/C mice. The results showed that PSPP was a pyran polysaccharide with 1 → 2, 1 → 2, 6, 1 → 4, 1 → 4, 6 glycosidic bonds in an α-configuration. In vivo experiments showed that PSPP could relieve diarrhea and improve the structural damage in the ileum caused by lincomycin hydrochloride. In addition, treatment with PSPPs decreased the levels of IL-1β, IL-6 and TNF-α but increased the level of IL-10 in the intestines of mice (p < 0.01). The results of 16S rRNA sequencing showed that PSPPs changed the composition and diversity of the intestinal flora of mice with AAD. In addition, PSPP treatment increased the content of short-chain fatty acids (p < 0.01). These results revealed that PSPPs regulated the intestinal flora, balanced fatty acid metabolism, and relieved the symptoms of diarrhea to a certain extent in mice.