Gut Microbiota and Insulin Resistance: Mechanisms, Therapeutic Strategies, and Future Directions

The gut microbiota, a complex ecosystem of microorganisms within the gastrointestinal tract, has emerged as a critical regulator of metabolic health. This review explores the intricate relationship between gut microbiota and insulin resistance, focusing on the underlying mechanisms, compositional changes, and therapeutic implications. Dysbiosis, characterized by reduced microbial diversity and an imbalance between beneficial and pathogenic species, contributes to insulin resistance through impaired short-chain fatty acid (SCFA) production, gut barrier dysfunction, and systemic inflammation. Key bacterial taxa, such as Akkermansia muciniphila and Faecalibacterium prausnitzii, play pivotal roles in maintaining metabolic homeostasis, while alterations in the Firmicutes-to-Bacteroidetes ratio and increased endotoxin production exacerbate metabolic dysfunction. Evidence suggests that modifiable factors, including diet, physical activity, and microbiota-targeted therapies like probiotics, prebiotics, and fecal microbiota transplantation (FMT), offer potential avenues for restoring microbial balance and mitigating insulin resistance. Despite advancements, research in this field faces challenges, including methodological variability, interindividual microbiota differences, and a need for standardized clinical approaches. Future studies should focus on long-term, large-scale interventional trials, personalized microbiota-based interventions, and elucidation of the gut microbiota's molecular mechanisms. This review underscores the promising role of gut microbiota in managing insulin resistance and highlights opportunities for integrating microbiota-targeted strategies into clinical practice.