The relationship between starch digestion and glucagon-like peptide-1 secretion: implications for functional food design to improve glycemic control

The escalating global prevalence of metabolic syndromes has intensified the search for effective dietary strategies. As the primary dietary carbohydrate, starch plays a critical role in postprandial metabolism by virtue of its digestion dynamics. A key regulator in this process is the gut hormone glucagon-like peptide-1 (GLP-1), which governs glycemic control and satiety. This review synthesizes recent advances in our understanding of the interplay between starch digestion and GLP-1 secretion, which is a potentially important yet not yet fully explored physiological pathway. Notably, slowly digestible and resistant starches appear to promote GLP-1 release by delivering their digestion by-products, namely glucose and short-chain fatty acids, respectively, to distal gut L-cells. Conversely, GLP-1 modulates starch digestion and suppresses appetite by delaying gastric emptying, an effect mediated by both the endocrine pathway and local paracrine activation of vagal afferents (via GLP-1 receptors) within the gut-brain axis. By examining the mechanistic links between starch multiscale structure, spanning from molecular architecture to food matrix integrity, and enteroendocrine function, we propose a framework for designing functional foods that support endogenous GLP-1 activity. Such synergistic strategies offer a promising and sustainable complement to pharmacological interventions for improving postprandial glycemia and overall metabolic health.