In vitro assessment of the effect of four polysaccharides on intestinal bacteria of mice with colitis

Abstract

Polysaccharides are typically resistant to digestion in the gastrointestinal tract and are instead degraded by gut microbiota in the colon. As such, they are commonly employed as carriers for colon-targeted drugs, with the potential to regulate gut microbiota. Pectin, carrageenan, guar gum, and xanthan gum are commonly used polysaccharide carriers, but their degradation in the gut microbiota under colitis conditions as well as their effects on gut microbiota remains unclear. In this study, we performed the in vitro fermentation of these four polysaccharides using colonic content microbiota from mice with colitis and evaluated the degree of polysaccharide degradation and the effects on pH, short-chain fatty acids, and gut microbiota. Our findings indicate that pectin and guar gum had a greater degree of degradation and promoted the production of butyrate, inhibited the proliferation of harmful bacteria (e.g., Enterobacteriaceae), and increased beneficial bacteria (e.g., Bifidobacterium). In contrast, carrageenan and xanthan gum promote the proliferation of Enterobacteriaceae. These results provide theoretical guidance for the selection of drug delivery carriers for inflammatory bowel disease treatment and provide information on the relationship between polysaccharides and gut microbiota.