Gut Microbiome and Immune System Crosstalk in Chronic Inflammatory Diseases: A Narrative Review of Mechanisms and Therapeutic Opportunities.

The gut microbiota, a complex community of trillions of microorganisms residing in the gastrointestinal tract, plays a vital role in maintaining host health and regulating a wide range of physiological functions. Advances in molecular biology have greatly expanded our understanding of the dynamic interactions between the gut microbiome and the immune system. Disruption of this microbial community, known as dysbiosis, can compromise epithelial barrier integrity, trigger aberrant immune activation, and lead to the production of proinflammatory metabolites. These changes are increasingly recognized as contributing factors in the pathogenesis of chronic inflammatory diseases. Emerging research highlights the gut microbiota as a key modulator of immune homeostasis, influencing both local and systemic inflammatory processes during the initiation and progression of these diseases. Understanding the mechanisms underlying gut microbiota-immune interactions will offer new avenues for therapeutic interventions. This review focuses on six representative chronic inflammatory diseases, including rheumatoid arthritis, inflammatory bowel disease, psoriasis, systemic lupus erythematosus, asthma, and vasculitis, all of which are characterized by dysregulated immune responses and persistent inflammation. Our goal is to synthesize the recent research on the role of gut microbiome in the pathogenesis of the diseases listed above and provide insights into the development of microbiota-based therapies, particularly fecal microbiota transplant, dietary modifications, prebiotic and probiotic interventions, for their treatment.