Stomach Bugs and Other Unpleasant Infections May Help Prevent RA

We rarely think of an infection as a good thing, but recent evidence suggests that certain bugs may help protect against rheumatoid arthritis (RA). In a study conducted in Sweden, researchers found that people with recent stomach or urinary tract infections might have a lower risk of developing RA.

A potential connection between infections and RA isn’t a new concept. For many years researchers have thought that infections might cause or activate RA, but they haven’t found enough evidence to support this theory. Now they’re putting a different spin on the topic and looking at infections as protection against RA.

It turns out that changes in the composition of bacteria in the gut and other mucous membranes (such as the genitals) may have an effect on the immune system and inflammatory responses—an effect that may protect against RA. Because infections can cause these types of changes, researchers are now turning to infection not as a cause of RA, but as a possible protection against the disease.

To test this theory, researchers created a study that compared people with RA to people without RA who were the same age and sex and lived in the same area. They looked for a history of infections during the two years before the study. Types of infections included gastroenteritis (stomach infection), urinary tract infection, genital infection, prostatitis (swelling of the prostate), sinus infection, tonsillitis, and pneumonia.

According to the study’s findings, some very unpleasant infections might have a bright side when it comes to RA. Gastroenteritis, for example, as well as urinary tract and genital infections and prostatitis were all linked with a lower risk of RA.

Other infections, however, didn’t appear to protect against RA and remain a regular nuisance. These included sinusitis, tonsillitis, and pneumonia.

What does this link between RA and stomach and urinary tract infections mean for you? Don’t fear—it’s not a call to pick up a bug in order to prevent RA. But these findings do help researchers recognize the role that the bacterial makeup of the gut and other mucous membranes might play in the development of RA. This understanding will likely play an important role in future RA research and treatment.

Reference: Sandberg ME, Bengtsson C, Klareskog L, et al. Recent Infections Are Associated with Decreased Risk of Rheumatoid Arthritis: a Population-Based Case-Control Study. Annals of Rheumatic Diseases. doi:10.1136/annrheumdis-2014-206493.