Abstract: Resistant starch (RS), as a novel dietary fiber, has shown promising potential in the intervention of type 2 diabetes mellitus (T2DM) due to its unique resistance to digestion and metabolic regulatory functions. This paper systematically reviews the structural characteristics, digestion resistance mechanism, and metabolic regulatory effect of RS on T2DM. First, the anti-digestive mechanism of RS is elucidated from the perspectives of molecular conformations, crystal types, and the synergistic effects of multi-component food matrices. Second, the molecular mechanisms by which RS alleviates T2DM through reshaping the gut microbiota, regulating the short-chain fatty acids (SCFAs)-bile acid metabolic network, repairing the intestinal barrier, and modulating insulin signaling pathways are thoroughly discussed. Finally, the innovative applications of RS in targeted delivery systems, controlled release technologies for drug delivery, and functional food development are highlighted. Furthermore, we propose that precise nutritional intervention by integrating smart responsive carriers and multi-omics technologies would be a future direction. This review aims to provide theoretical support for the fundamental research and clinical translation of RS in the prevention and treatment of metabolic diseases.

Key words: resistant starch; type 2 diabetes mellitus; structural characteristics; metabolic regulation; nutritional intervention