title: The intestinal microbiome in spondyloarthritis.
abstract: OBJECTIVE
  Microbial dysbiosis in the gut is emerging as a common component in various inflammatory disorders including spondyloarthritis (SpA). The depth of this influence has begun to be realized with next-generation sequencing of the gut microbiome providing unbiased assessment of previously uncharted bacterial populations.
  
  
  RESULTS
  Decreased numbers of Firmicutes, a major phyla of gut commensals, especially the species Faecalibacterium prausnitzii and Clostridium leptum have been found in various inflammatory disorders including SpA and inflammatory bowel disease (IBD), and could be an important link between SpA and gut inflammation. Multiple studies in ankylosing spondylitis, psoriatic arthritis, juvenile SpA, and animal models of SpA are revealing common bacterial associations among these diseases as well as IBD.
  
  
  CONCLUSIONS
  We are beginning to appreciate the complex relationship between the gut microbiome and host immune regulation and dysregulation in health and disease. Potentially important differences have been revealed in SpA, but cause and effect relationships remain far from established. Many critical questions remain to be answered before we can apply new knowledge to improve therapeutics in SpA.
authors.affiliation: aPediatric Translational Research Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland bDivision of Arthritis and Rheumatic Diseases, Oregon Health & Science University, Legacy Devers Eye Institute, Portland, Oregon, USA.
authors.forename: Tejpal
authors.initials: T
authors.lastname: Gill
authors.forename: Mark
authors.initials: M
authors.lastname: Asquith
authors.forename: James T
authors.initials: JT
authors.lastname: Rosenbaum
authors.forename: Robert A
authors.initials: RA
authors.lastname: Colbert
mesh_terms: D000818:Animals; D015535:Arthritis, Psoriatic / Q000276:immunology / Q000382:microbiology; D004195:Disease Models, Animal; D064806:Dysbiosis / Q000503:physiopathology; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000276:immunology / Q000382:microbiology; D007422:Intestines / Q000276:immunology / Q000382:microbiology*; D025241:Spondylarthritis / Q000276:immunology / Q000382:microbiology*; D013167:Spondylitis, Ankylosing / Q000276:immunology / Q000382:microbiology