<i>In vitro</i> fermentation characteristics of polysaccharide from <i>Scrophularia ningpoensis</i> and its effects on type 2 diabetes mellitus gut microbiota

Analysis of chemical compositions indicates that the total sugar content of SNP was found to be as high as 87.35 ± 0.13% (w/w). SNP treatment significantly improved the gas volume and composition in T2DM fecal matter. Moreover, intestinal flora degraded SNP to produce SCFAs, thus regulating SCFA production and composition. Metabolomic analysis implied that SNP shows potential to regulate the five gut metabolites (L-valine, L-leucine, L-isoleucine, L-alanine, and xylitol) in T2DM fecal matter. Furthermore, dysbiosis of gut microbiota induced by T2DM was reversed by SNP. The evidence includes decreasing <i>Firmicutes</i>/<i>Bacteroidota</i> ratio at phylum level promoting proliferation of the bacterial abundance of <i>Dorea</i>, <i>Parabacteroides</i>, <i>Faecalibacterium</i>, and <i>Lachnospira</i> and decreased bacterial abundance of <i>Escherichia-Shigella</i>. Based on these findings, the action mechanism of SNP against T2DM was clarified by reshaping microbiota and regulating intestinal metabolites, and a novel target was provided for interventions of T2DM.