Recrystallized Resistant Starch: Structural Changes in the Stomach, Duodenum, and Ileum and the Impact on Blood Glucose and Intestinal Microbiome in Mice

The structure and properties of resistant starch (RS)and its digestiveproducts were assessed in mice. Digestion of recrystallized (groupRS3, including RS3a and RS3b) and control RS (RS2, RS4, and RS5) inthe stomach, duodenum, and ileum of mice was systematically analyzedalong with in vivo digestive degradation of RS3.RS3a and RS3b significantly reduced the release of blood glucose.During in vivo digestion, the proportion of ultrashortand A chains in the RS3a and RS3b digestive residues gradually increased,whereas the proportion of B1 and B2 chains gradually reduced. B3+chain proportions did not change. The final digestive residues inthe ileum (RS3a-I90 and RS3b-I90) maintained a high proportion ofsuitable chain length, accounting for more than 60%. The crystallinestructure of RS3a-I90 was weakened, indicating the hydrolysis of partialcrystal structure. In comparison, RS3b-I90 maintained an orderly crystallinestructure, indicating its higher resistance to enzymatic hydrolysis. In vivo experiments showed that RS could maintain the normalgrowth of mice and effectively control weight gain. RS3a significantlyincreased the concentrations of acetic, propionic, and butyric acids,while reducing the abundance of Firmicutes to Bacteroidetes ratio,further confirming the benefits of RS3 in gastrointestinal health.