ROLE OF GUT MICROBIOTA IN METABOLIC SYNDROME: A SYSTEMATIC LITERATURE REVIEW

Abstract

Metabolic Syndrome (MetS) is a multifactorial condition, which is said to be insulin resistant, central obese, dyslipidemic, and hypertensive, posing significant risks to cardiovascular disease and diabetes mellitus type 2. There is accumulating evidence to support the idea that gut microbiota changes in composition and functionality are a significant cause of MetS pathogenesis. Such a systematic literature review was conducted in order to summarize existing evidence on the contribution of gut microbiota dysbiosis to metabolic syndrome development and progression and to assess the effects of microbiota-focused interventions on metabolic outcomes. PubMed, Web of Science, and Scopus were also searched thoroughly including studies published to October 2025, with Google Scholar and manual screening of references. Included were observational studies and interventional studies that used human participants with metabolic syndrome or its sub-units. The Newcastle-Ottawa Scale and Cochrane Risk of Bias tool were used to extract data and determine the quality of the data, respectively. When needed, random-effects meta-analysis was implemented in order to determine the pooled effects of microbiota-modulating interventions on metabolic parameters. Ninety two studies were found to fulfill the inclusion criteria of which 48 studies were found to be eligible to undergo quantitative synthesis. Microbial diversity in individuals with metabolic syndrome was continuously decreased, Firmicutes to Bacteroidetes ratios were disturbed, and beneficial genera were lost, including Akkermansia and Bifidobacterium, and inflammatory ones were enriched. Mechanistically, dysbiosis was linked with a decrease in the short-chain fatty acid production, an increase in gut permeability, endotoxemia in the metabolism, and high levels of trimethylamine-N-oxide, which led to insulin resistance and systemic inflammation. Meta-analysis has proved a significant change in fasting glucose, triglycerides, HOMA-IR and inflammatory markers after probiotic, prebiotic and dietary interventions. Dietary patterns based on the Mediterranean and plant were linked to a greater microbial variety and a better cardiometabolic picture. The role of gut microbiota dysbiosis in the pathophysiology of metabolic syndrome occurs via metabolism-,inflammatory-, and immunomodulatory-linked pathways. There is a positive therapeutic potential in microbiota-targeted interventions, especially dietary change and probiotic supplementation. Additional longitudinal and mechanistic research is justified to deal with the causality and design of customized microbiome-based treatment plans to manage the metabolic syndrome.