Gut Microbiota and Metabolic Syndrome: A Narrative Review

Obesity is a major global health problem and is closely associated with a broad range of metabolic disorders, including metabolic syndrome (MetS), dyslipidemia, hypertension, atherosclerosis, type 2 diabetes mellitus, and cardiovascular disease. The gut microbiota plays a central role in maintaining intestinal epithelial integrity, regulating glucose and lipid metabolism, and modulating immune function. Through the gut-brain axis, it also contributes to appetite regulation and energy homeostasis by influencing the release of anorexigenic hormones. Dysbiosis, including alterations in the relative abundance of major bacterial phyla such as Firmicutes and Bacteroidetes, has been associated with increased intestinal permeability, metabolic endotoxemia, and chronic low-grade inflammation, all of which may contribute to the development of obesity and insulin resistance. Diets rich in plant-derived fiber can beneficially shape gut microbiota composition. Bacterial fermentation of dietary fiber produces short-chain fatty acids (SCFAs), including butyrate, acetate, and propionate, which contribute to intestinal barrier integrity, inflammatory regulation, immune regulation, and metabolic homeostasis. Overall, the interaction between gut microbiota, diet, and host metabolic pathways represents a promising field for therapeutic and nutritional interventions aimed at preventing and managing MetS and metabolic diseases.