Rheumatoid arthritis is an autoimmune disease that affects the joints. It seems to be multifactorial and involve genetic and environment factors, and very probably the intestinal and oral microbiota.
An incapacitating disease
Rheumatoid arthritis (RA) is an autoimmune disorder that affects around 0.3% of the world population,1,2 primarily pre-menopausal women. It is characterized by chronic inflammation of the synovial membrane in the joints, and it progresses in flares. Beyond pain, it leads to progressive deformation followed by destruction of the joints.3
The disease has multiple causes: genetic predisposition, emotional shock, and lastly environmental factors.3 Intestinal4,5 and oral4,6 microbiota also seem to play a role in the development and severity of the disease. Preclinical studies have shown evidence of changes in the intestinal flora. Their results indicate that these anomalies are also observed in inflammatory bowel diseases: reduced microbial diversity and a reduction in the frequency of Firmicutes known for their immunoregulatory properties, which are partially corrected during RA treatment.7 However, it was observed that patients suffering from RA have an increase in Prevotella copri in the stool, which correlates with HLA genotype.
Oral microbiota suspected
The connection between RA and the oral microbiota has long been suspected because of the frequency of severe periodontitis in these patients,6,8,9,10 and it seems to be confirmed by recent work. DNA of gingival pathobionts, such as Porphyromonas gingivalis, for example, was found in the synovial fluid of subjects with RA.6,10
New therapeutic approaches
Treatment currently consists of the use of analgesics, anti-inflammatory drugs, immunosuppressants, and biotherapies. Nevertheless, newly discovered associations between RA and the microbiota open new perspectives for the development of biomarkers, or even new therapeutic approaches that could include probiotics.7,11,12
1. GuilleminF et al. Prevalenceofrheumatoidarthritis in France: 2001. Ann Rheum Dis 2005;64:1427–30.
2. American College of rheumathology. http://www.rheumatology.org/Learning-Center/Statistics/Prevalence-Statistics
3. Dossier Inserm sur la polyarthrite rhumatoïde, février 2011 http://www.inserm.fr/thematiques/physiopathologie-metabolisme-nutrition/dossiers-d-information/polyarthrite-rhumatoide
4. Zhang X, Zhang D, Jia H, et al. The oral and gut microbiomes are perturbed in rheumatoid arthritis and partly normalized after treatment. Nat Med 2015 ; 21 : 895-905. http://www.nature.com/nm/journal/v21/n8/abs/nm.3914.html
5. Schaeverbeke T, Truchetet ME, Richez C. Gut metagenome and spondyloarthritis. Joint Bone Spine 2013 ; 80 : 349-52. https://www.ncbi.nlm.nih.gov/pubmed/23806346
6. Scher JU, Bretz WA, Abramson SB. Periodontal disease and subgingival microbiota as contributors for rheumatoid arthritis pathogenesis : modifiable risk factors? Curr Opin Rheumatol 2014 ; 26 : 424-9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4128331/
7. Breban M. Joint Bone Spine. 2016 Dec;83(6):645-649. doi: 10.1016/j.jbspin.2016.04.005. Epub 2016 May 26. Gut microbiota and inflammatory joint diseases. https://www.ncbi.nlm.nih.gov/pubmed/27238190
8. Scher JU, Abramson SB. Periodontal disease, Porphyromonas gingivalis, and rheumatoid arthritis: what triggers autoimmunity and clinical disease? Arthritis Res Ther 2013 ; 15 : 122. https://www.ncbi.nlm.nih.gov/pubmed/24229458
9. Scher JU, Ubeda C, Equinda M, et al. Periodontal disease and the oral microbiota in new-onset rheumatoid arthritis. Arthritis Rheum 2012 ; 64 : 3083-94. https://www.ncbi.nlm.nih.gov/pubmed/22576262
10. Wolff B, Berger T, Frese C, et al. Oral status in patients with early rheumatoid arthritis: a prospective, case-control study. Rheumatology 2014 ; 53 : 526-31. https://www.ncbi.nlm.nih.gov/pubmed/24273047
11. Yeoh N, Burton JP, Suppiah P, Reid G, Stebbings S. The role of the microbiome in rheumatic diseases. Curr Rheumatol Rep 2013 ; 15 : 314. https://www.ncbi.nlm.nih.gov/pubmed/23378145
12. Wang P, Tao JH, Pan HF. Probiotic bacteria: a viable adjuvant therapy for relieving symptoms of rheumatoid arthritis. Inflammopharmacology. 2016 Oct;24(5):189-196. Epub 2016 Aug 31. https://www.ncbi.nlm.nih.gov/pubmed/27581587