Complexed Tartary buckwheat starch with ginger exosomes modulates digestion resistance and gut microbiota to alleviate metabolic dysregulation in T2DM mice

Resistant starch (RS) stabilizes postprandial blood glucose levels through multiple mechanisms and offers distinct advantages in preventing and managing metabolic diseases such as diabetes. This study introduces a novel plant exosome-starch composite system, combining Tartary buckwheat starch (TBS) and ginger exosomes (GELNs), referred to as the TBS-GELNs composite resistant starch (GTBS). Multi-scale physicochemical analysis revealed the molecular interaction mechanisms: composite formation significantly altered the microstructure of gelatinized starch. GELNs interacted with TBS through hydrogen bonds, enhancing starch crystallinity and short-range ordering, thus reducing its digestibility. The metabolic effects of GTBS on type 2 diabetes mellitus (T2DM) mice were further examined. The results indicated that GTBS markedly decreased fasting blood glucose and lipid levels, alleviated some organ damage, and improved gut microbiota composition by enhancing the structure and abundance of beneficial bacterial populations. This study provides novel insights and a theoretical basis for the regulation of postprandial blood glucose via composite starch-based biomolecules, offering promising strategies for developing staple food products that integrate nutritional value with biological activity.