New studies suggest that bacteria in the gut may predict susceptibility to rheumatoid arthritis (RA), be used by physicians to prevent disease onset, and that altering the gut microbiome composition can improve RA symptoms.
The findings were published from two studies led by Veena Taneja, PhD, an immunologist at the Mayo Clinic’s Center for Individualized Medicine.
“These are exciting discoveries that we may be able to use to personalize treatment for patients,” Taneja said in a press release.
The first study, “An expansion of rare lineage intestinal microbes characterizes rheumatoid arthritis,” published in Genome Medicine, identified microbial changes that could function as biomarkers and predict disease status in RA. The researchers found that RA patients have decreased microbial diversity but abundance of specific rare bacteria.
“Using genomic sequencing technology, we were able to pin down some gut microbes that were normally rare and of low abundance in healthy individuals, but expanded in patients with rheumatoid arthritis,” said Taneja.
One specific type of rare bacteria found in high numbers in RA patients, collinsela, may correlate with RA by enhancing intestinal permeability and increasing the expression of pro-inflammatory molecules that can lead to the inflammation. Collinsela’s role was confirmed when arthritis-susceptible mice were given the bacteria and then developed increased RA incidence and severity.
The findings could help physicians predict who is at risk of developing RA and what the course of the disease could be — which may lead to prevention and treatment methods.
In the second study, “Human Gut-Derived Prevotella histicola Suppresses Inflammatory Arthritis in Humanized Mice,” published in Arthritis and Rheumatology, a team led by Taneja explored the role of bacteria with immunosuppressive properties in arthritis-susceptible mice.
Investigators found that Prevotella histicola, a bacteria commonly found in gastrointestinal and urogenital mucosal surfaces, was able to prevent or decrease the severity of arthritis in mice when orally ingested with a coating that only disintegrates in the intestines.
The treatment was found to produce fewer side effects than those observed with other standard of care treatments, which suggests that it may be a potential therapeutic approach for RA patients.