THURSDAY, Feb. 5, 2015 (HealthDay News) — People with recent gut, urinary tract or genital infections may be less likely to develop rheumatoid arthritis, new research says.

The findings are “particularly interesting” in light of recent research suggesting that digestive system bacteria may play a role in the development of rheumatoid arthritis, researchers from the Karolinska Institute in Stockholm, Sweden, said.

The study included almost 6,500 people from Sweden. Their average age was 52. About 70 percent were women. More than 2,800 people in the group were diagnosed with rheumatoid arthritis between 1996 and 2009.

According to the study, having a gut infection within the preceding two years was associated with a lower risk of rheumatoid arthritis by 29 percent. A urinary tract infection was associated with a 22 percent lower risk, while a genital infection was associated with a 20 percent lower risk.

People who had all three types of infections in the preceding two years were 50 percent less likely to develop rheumatoid arthritis, according to the researchers.

Gut, urinary tract or genital infections within the past year did not affect rheumatoid arthritis risk, nor did recent respiratory infections.

Researchers only found an association between previous infections and risk of rheumatoid arthritis, not a cause-and-effect link.

The study was published online in the journal Annals of the Rheumatic Diseases.

One explanation is that certain infections may alter the types of bacteria in the digestive system, the researchers said.

They also noted that antibiotics used to treat gut, urinary and genital infections are effective in treating rheumatoid arthritis.

— Robert Preidt

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SOURCE: Annals of the Rheumatic Diseases, news release, Feb. 4, 2015