The short-chainfatty acid propionate, produced through fermentation of undigested carbohydrates ordietary fiber by the gut microbiota, has shown to alter the enteroendocrine cells andincrease the number of L cells (35).Understanding how different macronutrients and food groups influence fasting GLP-1 plasmalevels and glucose homeostasis is imperative to form effective dietary guidelines inpeople at risk or living with T2D. The gene discussed is GLP1R; the disease is type 2 diabetes mellitus.