Gut Microbiota and Autoimmune Diseases: The Therapeutic Potential of Probiotics.

In recent years, increasing attention has been directed toward the role of gut microbiota in the pathogenesis of autoimmune diseases such as type 1 diabetes (T1D), rheumatoid arthritis (RA), and multiple sclerosis (MS). Numerous studies have shown that gut dysbiosis-an imbalance in the intestinal microbial community-can influence host immune responses by modulating inflammatory pathways, gut barrier integrity, and immune cell function. Patients with T1D, RA, and MS often exhibit a decreased abundance of anti-inflammatory bacteria (e.g., Faecalibacterium prausnitzii) and an overrepresentation of pro-inflammatory taxa (e.g., Prevotella copri). Probiotics and fecal microbiota transplantation have shown therapeutic potential by restoring microbial balance, enhancing short-chain fatty acid production, supporting regulatory T cell function, and suppressing pro-inflammatory Th1 and Th17 responses. Despite promising results, the efficacy and safety of these interventions remain uncertain, especially in immunocompromised individuals. The lack of standardization in probiotic formulations, limited large-scale clinical trials, and unknown long-term effects restrict their widespread application. Moreover, individual variability in microbiota composition and disease phenotype complicates the development of universally effective treatments. Further rigorous research is necessary to better understand the immunological mechanisms involved and to develop safe, personalized, and effective microbiota-based therapeutic strategies. Until then, probiotics and FMT should be considered as adjunctive therapies within comprehensive treatment plans for autoimmune diseases rather than standalone solutions.