Anti-obesity effects of α-amylase inhibitor enriched-extract from white common beans (Phaseolus vulgaris L.) associated with the modulation of gut microbiota composition in high-fat diet-induced obese rats

α-Amylase inhibitor (α-AI) has great potential to treat obesity. In this study, α-Amylase inhibitorAI enriched extract (α-AIE) with specific activity of 1027.1±154.2 (U mg-1 protein) were prepared from white common bean (Phaseolus vulgaris L.) seeds. has great potential to treat obesity. Base on its starch blocker role, the indirect modulating effect on the gut microbiota composition was hypothesized. This study aimed to verify Itsthe anti-obesity effect and the gut microbiota modulation properties were verified of α-AIE in high-fat diet-induced obese rats. Intake of α-AIE significantly reduced the body weight gain and improved the serum lipid levels of obese rats (p<0.05). In addition, rats fed the α-AIE diet exhibited higher total short-chain fatty-acid (SCFA) concentrations (p<0.05) in their colonic contents. β-Diversity analysis, principal components analysis and a Venn diagram showed that α-AIE administration changed the gut microbiota composition of obese rats. At the phylum level, the relative abundances of Firmicutes and Proteobacteria decreased and the relative abundances of Bacteroidetes and Akkermansia increased. In addition, 89 operational taxonomic units (OTUs) significantly responding to high-fat diet and 30 OTUs significantly responding to α-AIE were identified. The OTUs enriched by α-AIE were mainly assigned to putative SCFA-producing bacteria, including Bacteriodes, Butyricoccus, Blautia and Eubacterium. Twenty-two OTUs were found to be significantly correlated with obesity indexes. Taken together, the present results suggest that intake of α-AIE attenuated obesity and modulated gut microbiota.