A Novel, Multifunctional Resistant Starch–Phenol Complex with Potential for Better Glycemic Control

Resistant starch (RS) with added functional properties, for example, starch-phenol complex, has considerable promise for reducing the risks of diet-related diseases such as type 2 diabetes (T2D). In this study, a novel starch-phenol complex was prepared with amylose (AM) and 10-gingerol (10G) to study the potential beneficial effects on blood glucose control. The AM and 10G self-assembled into an AM-10G complex with V₆- and V₇-type crystallites. The rate of amylolysis of the AM-10G complex was much slower than that of the AM-lauric acid (LA) complex. During enzymic digestion of the AM-10G complex, the α-amylase activity was inhibited greatly and approached zero at 45 min. In separate experiments, 10G suppressed glucose transport rate by 60% across a Caco-2 cell monolayer and also downregulated the expression of mRNA for the two glucose transporter genes, GLUT2 and SGLT1. In vitro fecal fermentation analyses showed that AM-10G complex promoted the proliferation of Lachnospiraceae_NK4A136_group and Lachnospiraceae_UCG_004 associated with improved postprandial glycemia. The present study demonstrates that AM-10G complex has potential for glycemic control due to the inhibitory effects on the amylolytic process and glucose transporters involved in uptake of glucose into the bloodstream, as well as the modulation of gut microbiota associated with glycemic control.