Unraveling the Anti-Obesity Potential of White Kidney Bean α-Amylase Inhibitors: Mechanistic Insights From Enzyme Kinetics to Gut Microbiota Modulation

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.