A Second Look at the Link Between Arthritis and Microorganisms

In a review article published in March issue of the Current Opinion in Rheumatology, researchers point to evidence that shows that the microorganisms inside our bodies, could play a role in the development of arthritis, but it also could be used as therapeutic pathway.

The researchers point to two recurring themes in the literature:  (1) changes in microbiota in people with arthritis and (2) established attempts by physicians to treat arthritis by manipulating the microbiota.

“This is a rapidly developing area of research. There are tantalizing hints that interventions targeting the microbiota may become therapeutically viable for some types of inflammatory arthritis,” wrote the researchers who were led by Simon Milling of the University of Glasgow in the United Kingdom.

Microbial communities respond to changes in health and are altered in people with arthritis.

“Understanding the complex relationships between the microbiota and the body may enable us to deliberately manipulate these organisms and provide additional therapeutic options for people with arthritis,” the researchers wrote.

Microorganisms are known to play a role in the development of other diseases. A Helicobacter pylori (H. pylori) infection can predispose patients to gastric cancer. And, in Crohn’s disease, changes in the intestinal microbiota are common in patients diagnosed with Crohn’s disease.

In people with arthritis, there have been documented changes in the microbiota in the lower intestinal tract and in the oral cavity, but what remains to be seen is whether the microbiota directly contributes to the pathogenesis of arthritis.

“One study showed a correlation between altered bacterial community structure in periodontal samples from people with early rheumatoid arthritis (RA), observing increases in Prevotella and Leptotrichia species in patients independently of the status of their periodontal disease,” the authors wrote.

Another study showed higher frequency of Prevotella and a reduction of Bacteriodes in stool samples from patients with new-onset untreated rheumatoid arthritis. In patients with psoriatic arthritis, one study showed a decreased fecal bacterial diversity, including reductions in Coprococcus, Akkermansia, Ruminococcus and Pseudobutyrivibrio species. [[{"type":"media","view_mode":"media_crop","fid":"45720","attributes":{"alt":"@CreativeImages/Shutterstock.com","class":"media-image media-image-right","id":"media_crop_6811899335589","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5254","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":"@CreativeImages/Shutterstock.com","typeof":"foaf:Image"}}]]

In children with enthesitis-related arthritis, the faecal microbial profile was also altered. A subset of these children had an increased Bifidobacterium and increased Akkermansia muciniphila, but decreased Lachnospiraceae and Faecalibacterium pausnitzii.  In both cases, the microbial imbalance was compared to that of inflammatory bowel disease.

“The microbiota encompasses approximately 100 trillion microorganisms living in the intestine alone, so pinpointing specific disease causing microorganisms is a Herculean task,” the authors wrote.

In most cases, an altered microbiome has been treated with a single, or multiple, strains of beneficial bacteria or yeasts; dietary modification and the use of prebiotics in the form of fibre supplementation and faecal microbial transplantation, but these treatments have had little benefit in patients with rheumatic diseases, despite positive results from animal studies, the authors wrote.

Pleaseclick here to learn more about this line of work, including the effect of a vegan diet on the microbiome.

References:

Bravo-Blas, Alberto; Wessel, Hannah; Milling, Simon. "Microbiota and arthritis: correlations or cause?"

The Current Opinion in Rheumatology

. March 2016 - Volume 28 - Issue 2 - p 161–167. doi: 10.1097/BOR.0000000000000261