Polysaccharides from red kidney bean alleviating hyperglycemia and hyperlipidemia in type 2 diabetic rats via gut microbiota and lipid metabolic modulation

Crude polysaccharides extracted from red kidney bean (RK) display significant antidiabetic activity in type 2 diabetic mice, but the underlying mechanism and the core functional component has not been elucidated. In this study, the antidiabetic effect and mechanism of RK are investigated by serum metabolomics and high-throughput sequencing. In addition, the key component was identified by evaluating the improvement on glucose and lipid homeostasis in type 2 diabetic rats. Our data indicated that RK relieved the symptoms of hyperglycemia, hyperlipidemia in STZ-induced diabetic rats. RK not only improved the metabolic disturbance by regulating the biosynthesis of unsaturated fatty acids, but also modified gut microbiota composition by selectively enriching in key genera of Bacteroides, Phascolarctobacterium, Succinivibrio, Blautia. We further found the purified polysaccharides (RKP) were identified as the core biofunctional component in RK. Our present studies provide evidence that RKP are potential effective dietary supplement for type 2 diabetic individuals.