Intestinal Microbes in Autoimmune and Inflammatory Disease

Abstract

Autoimmune diseases and chronic inflammatory disorders are characterized by dysregulated immune responses resulting in excessive and uncontrolled tissue inflammation. Multiple factors including genetic variation, environmental stimuli, and infection are all thought to contribute to continued inflammation and pathology. Current evidence supports the microbiota as one such factor with emerging data linking commensal organisms to the onset and progression of disease. In this review, we will discuss links between the microbiota and specific diseases as well as highlight common pathways that link intestinal microbes with multiple autoimmune and inflammatory diseases.

Gut microbiota-mediated secondary bile acids regulate dendritic cells to attenuate autoimmune uveitis through TGR5 signaling

“…Altered bile acids and gut microbiota composition in the feces of EAU mice Current studies have indicated that a dysregulation of gut microbiota plays a critical role in the development and the progression of several autoimmune diseases, including uveitis (Wu et al, 2020;Ye et al, 2018). However, how the gut microbiota plays its effect on uveitis is still not well clarified.…”

A Role for Folate in Microbiome-Linked Control of Autoimmunity

“…Whether dysbiosis represents the cause or result of IBD (reviewed in [ 38 ]), it is a correlated biomarker of extraintestinal inflammatory disease (reviewed in [ 25 , 39 ]). While mechanistic evidence is still limited, dysbiosis has long been linked to AD [ 40 ], including noninfectious uveitis [ 41 – 43 ], (reviewed in [ 25 ]), often occurring simultaneously with acute flare-ups of colitis [ 44 ]. Thus, it can be seen that dysbiosis and similar microbiota-related environmental factors impact up to 70% of all AD [ 45 , 46 ], and while the etiology of IBD itself is not fully understood, it is considered to be the result of an interplay between environment/nutrition, microbiota, gastrointestinal immunity, and epigenetics.…”

Will the COVID‐19 pandemic trigger future occurrence of autoimmunity like Sjögren’s syndrome?

“…In addition, infections themselves, or the administration of anti‐pathogenic agents, may alter the host's intestinal homeostasis, causing dysbiosis in the gut flora. Recent investigations suggest that the alteration of gut homeostasis, or dysbiosis, is crucial in the induction of autoimmune diseases 19 . For instance, the potential role of a species of Gram negative bacteria in oral and gut microbiota, that is, Prevotella spp., in the pathogenesis of rheumatoid arthritis is attracting widespread interest 19,20 .…”

“…Recent investigations suggest that the alteration of gut homeostasis, or dysbiosis, is crucial in the induction of autoimmune diseases 19 . For instance, the potential role of a species of Gram negative bacteria in oral and gut microbiota, that is, Prevotella spp., in the pathogenesis of rheumatoid arthritis is attracting widespread interest 19,20 . As for SS, researchers have suggested an association between gut dysbiosis and the severity of dry eye 21 …”