Gut Microbiome and Its Interaction with Immune System in Spondyloarthritis

Abstract

Emerging evidence suggests there is a gut-joint axis in spondyloarthritis (SpA). In a study, subclinical gut inflammation occurred in nearly 50% of SpA. Chronic gut inflammation also correlated with disease activity in SpA. Trillions of microorganisms reside in the human gut and interact with the human immune system. Dysbiosis affects gut immune homeostasis and triggers different autoimmune diseases including SpA. The absence of arthritis in HLA-B27 germ-free mice and the development of arthritis after the introduction of commensal bacteria to HLA-B27 germ-free mice proved to be the important role of gut bacteria in shaping SpA, other than the genetic factor. The recent advance in gene sequencing technology promotes the identification of microorganisms. In this review, we highlighted current evidence supporting the link between gut and axial SpA (axSpA). We also summarized available findings of gut microbiota and its interaction with the immune system in axSpA. Future research may explore the way to modulate gut microorganisms in axSpA and bring gut microbiome discoveries towards application.

Do NSAIDs Take Us Away From Treatment Goals in Axial Spondyloarthritis: A Story About Dysbiosis or Just a Matter of Bias?

“…Dysbalances in Lachnospiraceae, Veillonellaceae, Prevotellaceae, Porphyromonadaceae, and Bacteroides spp. have been reported in patients with axSpA (13). However, these microbiome alterations seem strongly influenced by the genetic background.…”

“…Changes in gut microbiota composition are correlated with autoimmune diseases through the activation of the immune response, molecular mimicry, and increased intestinal permeability, among other mechanisms (13). Spondyloarthritis patients have a distinct gut microbiota compared to healthy controls, and 60-70% of patients with SpA present microscopic evidence of gut inflammation (13). Dysbalances in Lachnospiraceae, Veillonellaceae, Prevotellaceae, Porphyromonadaceae, and Bacteroides spp.…”

‘All disease begins in the gut’—the role of the intestinal microbiome in ankylosing spondylitis

“…Studies in HLA-B27 rat models suggest that both intestinal inflammation and impaired intestinal barrier function develop simultaneously [ 48 ]. It remains to be elucidated whether the integrity of the intestinal epithelium is compromised by intestinal inflammation or whether dysbiotic changes that precipitate epithelial breakdown (such as the intestinal bacterial upregulation of the tight junction modulator zonulin [ 49 ]) culminate in intestinal inflammation, or perhaps an interplay of both, are responsible for increased intestinal permeability.…”

“…MAIT cells are innate-like lymphocytes with antibacterial potential, which, when activated, induce a rapid immunological response with the production of pro-inflammatory cytokines, including both IL-17 and TNF-α [ 74 ]. Notably, germ-free mice display an absence of MAIT cells [ 75 ], and riboflavin metabolites of bacteria and fungi have been shown to activate MAIT cells [ 49 ]. Furthermore, MAIT cells have been demonstrated to be elevated in the serum of AS patients [ 73 ].…”

Editorial for Special Issue: Microbial and Autoimmune Disease

“…So and Tam, from the Chinese University of Hong Kong [ 10 ], have provided an updated and detailed review of the relationship between gut microbiome and Spondyloarthritis, an autoimmune inflammatory rheumatic disease occurring with a frequency ranging from 0.2 to 1.6%, mainly in <40-year subjects. The association between Spondyloarthritis and intestinal inflammatory pathologies, such as inflammatory bowel diseases (IBD), has been well-known for a long time.…”