Resistant starch-enriched rice varieties improve glucose homeostasis in diabetic mice via modulation of the intestine-liver-pancreas axis.

Diabetes mellitus is a prevalent chronic metabolic disease. At present, the efficacy and mechanism of different varieties of resistant-starch-rich rice (RSRR) diet in improving diabetes have not yet been thoroughly analyzed. This study evaluated the effects of a 6-week feeding period with two RSRR varieties, Yueyitang 1 (YYT) and Kangtangdao 1 (KTD), alongside a common rice cultivar, Meixiangzhan 2 (MXZ), using a high-fat diet-induced type 2 diabetic mouse model. Results demonstrated that RSRR reduced fasting blood glucose, blood lipids, and postprandial blood glucose response, with KTD being most effective. RSRR alleviated pancreatic tissue pathology, reduced serum insulin levels, and improved insulin resistance. It also mitigated hepatic steatosis and decreased gluconeogenesis via the AMPK-FoxO1-PEPCK-G6Pase pathway. Additionally, RSRR enhanced colon mucous cell count, up-regulated tight junction proteins ZO-1 and Occludin, and repaired intestinal barrier function. It activated the expression of GPR43, inhibited inflammatory factors Caspase-1 and ASC, promoted the secretion of intestinal hormones PYY and GLP-1, improved gut flora composition, and increased short-chain fatty acid production. Therefore, different RSRR varieties exhibited varying efficacy and mechanisms in improving diabetes, providing a theoretical basis for developing novel dietary interventions for diabetes.