Foods as Modulators of GLP-1 Secretion

Background/Objectives: Glucagon-like peptide-1 (GLP-1), which is released by enteroendocrine L-cells, is the primary incretin hormone and plays a pivotal role in glucose regulation, appetite control, and metabolic health. While GLP-1 receptor agonists offer significant therapeutic benefits, there is a growing interest in identifying foods that can increase endogenous GLP-1 production through physiological processes. However, the physiological impact of modulating GLP-1 through diet is modest compared with activating GLP-1 receptors pharmacologically. This narrative review summarizes the latest reports on how specific food matrices and gut microbiota-dependent pathways influence GLP-1 release, emphasizing their importance in precision nutrition. Methods: Literature published between 2001 and 2026 was reviewed, including experimental, clinical, and translational studies examining the effects of foods on GLP-1 secretion, L-cell activation, nutrient-sensing receptors, microbial metabolites, and metabolic outcomes. Evidence was synthesized for food categories such as fermented dairy products, fermented vegetables, whole grains, legumes, fiber-rich root vegetables, berries, grapes, green tea, turmeric and oily fish. Results: Foods modulate endogenous GLP-1 secretion through complementary pathways involving L-cell stimulation and the activation of receptors, including FFAR2, FFAR3, GPR119, TGR5 and FFAR4 (GPR120), as well as the production of microbial metabolites. Fermented dairy products, kimchi, kefir, Jerusalem artichokes, chicory root, oats, garlic, onions, berries, grapes, green tea and oily fish support incretin regulation through microbial fermentation, the generation of short-chain fatty acids (SCFAs), bile acid signalling and the release of bioactive compounds. These food matrices shape metabolite profiles more effectively than isolated nutrients, highlighting the importance of the interaction between whole foods and the gut microbiota. Conclusions: Foods rich in fermentable substrates, polyphenols, bioactive peptides and omega-3 fatty acids are promising dietary modulators of physiological GLP-1 activity. Taking into account microbiome characteristics, metabolic phenotype and individual postprandial responses could facilitate the development of personalized nutrition strategies to help prevent and manage obesity, type 2 diabetes and related cardiometabolic disorders.