2019, Vol. 1, Issue 1, Part A

Background and Objectives: Recent research has underscored the crucial function of gut microbiota in regulating immunological homeostasis and the pathogenesis of autoimmune disorders. Nonetheless, discrepancies persist concerning certain microbial modifications across several autoimmune disorders. This meta-analysis sought to assess the dysregulation of gut microbiota composition and functional characteristics in patients with autoimmune disorders relative to healthy controls.

Materials and Methods: A thorough literature review was conducted in the PubMed, Scopus, and Web of Science databases until 2019. Studies detailing gut microbiota makeup in individuals with autoimmune disorders were incorporated. Data were obtained from 60 patients and their comparable healthy controls in eligible trials. A random-effects model was used to look at microbial diversity indices, the relative abundances of important bacterial taxa, and projected functional pathways. The I² statistic was used to look at how different studies were, and Egger's test was used to look at publication bias.

Results: The meta-analysis demonstrated a notable decrease in ?-diversity indices (Shannon and Simpson) in autoimmune disease patients relative to controls (p < 0.01). Analysis of ?-diversity revealed distinct clustering of microbial communities, signifying compositional dysbiosis. Relative abundance analysis showed that genera that make short-chain fatty acids (SCFAs), like Faecalibacterium and Roseburia, were much less common, while pro-inflammatory taxa, like Enterobacteriaceae and Prevotella, were much more common. Functional pathway prediction showed that patients had less butyrate metabolism and more lipopolysaccharide biosynthesis pathways. Subgroup analysis pointed to disease-specific microbial signatures, especially in rheumatoid arthritis and systemic lupus erythematosus.

Conclusion: This meta-analysis shows that autoimmune illnesses have a lot of gut microbial dysbiosis, which means that the variety of gut microbes is lower, helpful commensals are less common, and metabolic functions are different. These results highlight the promise of gut microbiota-targeted therapies as supplementary approaches for the prevention and treatment of autoimmune diseases.