The Immune Response to Gut Bacteria in Spondyloarthritis: A Role in Pathogenesis?

Evidence for gut inflammation in the spondyloarthritides

Abstract

A link between Ankylosing spondylitis (AS) and gut inflammation is firmly established. The gut microbiota play a crucial role in the development of Ankylosing spondylitis. A defective intestinal mucosal barrier in combination with a dysfunctional immune response to luminal antigens has also been implicated. While specific bacteria have previously been postulated as a trigger for the development of disease, current evidence suggests that this is not the case. Advances in genetic research have enabled identification of several important modifier genes that appear to influence the penetrance of AS in HLA-B27-positive individuals. The function of these genes may also help to explain the mechanism of HLA-B27 in disease pathogenesis. The discovery of shared risk genes for AS and inflammatory bowel disease, in addition to immunological evidence for a shared pathogenesis have helped to increase our understanding of these two interrelated disorders. Moreover, a greater appreciation of the nature and frequency of gastrointestinal symptoms in patients with AS may assist in identifying patients with associated inflammatory bowel disease and hence influencing treatment decisions. In this review we discuss the evidence supporting the link between AS, gut bacteria, and the bowel.

Keywords

spondyloarthritis, ankylosing spondylitis, faecal micobiota, intestinal inflammation, crohn's disease, ulcerative colitis