Physicochemical properties, α-amylase and α-glucosidase inhibitory effects of the polysaccharide from leaves ofMorus albaL. under simulated gastro-intestinal digestion and its fermentation capabilityin vitroby human gut microbiota

The investigation aimed at determining the impact of sequential simulated digestion on the physicochemical properties and digestive enzymes inhibitory effects of the polysaccharides fraction (MLP-2) ofMorus albaL. leaves as well as itsin vitrofermentation behaviours. After artificial salivary, gastric and intestinal digestions, the chemical components and microstructure of MLP-2 were altered with significantly (P < 0.05) decreased molecular weight. The alpha-amylase and alpha-glucosidase inhibitory activities of MLP-2 were significantly (P < 0.05) improved throughout simulated digestion. MLP-2I, the intestinal digested fraction of MLP-2, could significantly (P < 0.05) decrease the pH value of fermented culture and increase the short-chain fatty acids (SCFA) concentrations, especially acetic, propionic and butyric acids. In conclusion, MLP-2 could be gradually degraded under simulated digestion with altered physicochemical properties and enhanced alpha-amylase and alpha-glucosidase inhibitory effects, and further utilised by human gut microbiota to decrease pH value and promote SCFA production.

Automated summary

The study showed that in simulated digestion, the chemical composition and structure of MLP-2 polysaccharides changed, with decreased molecular weight and increased inhibitory effects on digestive enzymes, leading to enhanced short-chain fatty acids production.