New research suggests that antibiotics may increase the risk of rheumatoid arthritis by altering the intestinal microflora. Can antibiotics cause rheumatoid arthritis?
Rheumatoid arthritis (RA) has poorly understood etiology. Genetics, smoking and hormones have been involved, but the emerging idea of microbial trigger (infection of a particular part of the body by a specific pathogen) has recently been studied in more detail. The role of epidemiological research has historically been important in generating hypotheses regarding the pathogenesis of diseases. Previous epidemiological studies have shown positive associations between bacteria such as P. gingivalis in periodontitis and an RA incident. These studies initiated a new area of microbiome research in RA pathogenesis, with conflicting findings between potential microbiological triggers and exploratory mechanistic studies
About 1.3 million adults in the United States live with rheumatoid arthritis (RA), an autoimmune condition that causes arthritis.
Scientists do not yet fully understand what causes RA, although they suspect a combination of genetic and environmental factors.
Some of the potential RA triggers include hormonal changes and exposure to some types of dust or fibers, as well as some viral or bacterial infections.
New research indicates the use of antibiotics and the changes that such use can lead to in a person’s intestinal microbiome as potential causes of RA.
Antibiotics can increase the risk of RA by 60%
By searching data from the Clinical Practice Research Datalink clinical care, the researchers found 22 677 cases of RA, matched them to over 90,000 healthy controls, and clinically observed these people for an average of 10 years before receiving a diagnosis of RA.
The analysis showed that the probability of developing RA was on average 60% higher in people receiving antibiotics.
In particular, those who received a prescription for one course of antibiotics had a 40% greater chance of developing RA, while those who took two courses had a 66% greater chance. Chances were even higher among those who took three or four courses.
Those who have recently taken antibiotics, i.e. in the last 1-2 years, had an 80% greater chance of developing RA. However, even prescriptions from the “distant past,” 5-10 years ago, were associated with 48% higher chances.
The type of infection people were taking antibiotics also affected the likelihood of developing RA.
Antibiotics in upper respiratory tract infections were more strongly associated with RA cases. However, the team did not identify this compound in untreated cases, suggesting that antibiotics raised the risk.
Prescriptions for antibiotics are associated with a higher risk of RA. This could be due to microbial disorder or underlying infections leading to risk, they say.