nyuAccording to researchers, a demonstration in humans indicates that rheumatoid arthritis (RA) may be facilitated in part by a specific species of intestinal bacteria known as Prevotella copri (P. copri). Laboratory scientists and clinical researchers in rheumatology at NYU School of Medicine reportedly used sophisticated DNA analysis in order to compare gut bacteria from fecal samples of patients with RA and healthy individuals.

The results suggest that P. copri was more abundant in newly diagnosed RA patients than in healthy individuals or patients with chronic, treated RA. The researchers add that the overgrowth of P. corpi was linked to fewer beneficial gut bacteria belonging to genera Bacteroides.

The researchers’ work in mouse studies encouraged them to look closer at RA patients, says Dan Littman, MD, PhD, Helen L. and Martin S. Kimmel Professor of Pathology and Microbiology and a Howard Hughes Medical Institute investigator. Littman calls the link between the bacteria and RA, “remarkable and surprising.”

Littman acknowledges however, “we cannot conclude that there is a causal link between the abundance of P. corpi and the onset of rheumatoid arthritis. We are developing new tools that will hopefully allow us to ask if this is indeed the case.”

To determine if the bacterial species correlated with RA, a news release from NYU Langone Medical Center/New York University School of Medicine states the researchers sequenced the 16S gene on 44 fecal DNA samples from newly diagnosed RA patients prior to immune-suppressive treatment. The release notes that 26 samples yielded from patients with chronic, treated RA, 16 samples came from patients with psoriatic arthritis, and 28 samples yielded from healthy individuals.

A total of 75% of stool samples from patients with newly diagnosed RA carried P. corpi compared to 21.4% of samples from healthy individuals, 11.5% from chronic, treated patients, and 37.5% from patients with psoriatic arthritis, researchers say. The research, the release states, may hold key treatment implications, as treated patients with chronic RA carried smaller populations of P. corpi.

Certain treatments may help stabilize the balance of bacteria in the gut, says study author Jose U. Scher, MD, director of the Microbiome Center for Rheumatology and Autoimmunity at NYU Langone Medical Center’s Hospital for Joint Diseases. Or, he adds, it may be that certain gut bacteria favor inflammation.

According to the release, the researchers aim to validate their results in regions beyond New York and determine whether the gut flora can be used a biological marker to guide treatment.

Source: NYU Langone Medical Center/New York University School of Medicine