Abstract
The global rise in obesity, driven largely by excessive carbohydrate consumption, highlights the demand for innovative dietary interventions targeting starch digestion. This study investigates the anti-obesity effects of α-amylase inhibitors (α-AI) extracted from white kidney beans, employing a multidisciplinary strategy encompassing botanical screening, enzyme kinetics, clinical trials, and gut microbiota profiling. Among 10 varieties evaluated, the A10 strain from Jilin Province demonstrated the highest α-AI activity, characterized by noncompetitive inhibition that remains effective across varying starch concentrations. In an 8-week randomized controlled trial, α-AI supplementation significantly reduced body weight, BMI, waist circumference, and hip circumference compared to placebo. Further, 16S rRNA sequencing revealed dual mechanisms: enrichment of SCFA-producing bacteria (e.g., Bifidobacterium and Bacteroides ovatus) and modulation of microbial lipid metabolic pathways. These results highlight α-AI as a dual-action anti-obesity agent, combining direct enzymatic inhibition with microbiome-mediated metabolic effects. By bridging phytochemical characterization with clinical outcomes, this work proposes a novel therapeutic approach that simultaneously targets carbohydrate absorption and gut microbial ecology, supporting the development of standardized α-AI formulations as potential nutraceuticals for metabolic syndrome.