More inflammatory bowel disease after antibiotic use

Any antibiotic use appears to increase the risk of inflammatory bowel disease, but antibiotics used for intestinal infections do the most. The risk is greatest one to two years following use, a research team found by analyzing more than 6.1 million people in Denmark. 5.5 million (91 percent) had been prescribed at least one course of antibiotics between 2000 and 2018. During the same period, 36,017 people were diagnosed with ulcerative colitis and 16,881 with Crohn’s disease.

Taking antibiotics was associated with a higher risk of developing these conditions: those aged 10 to 40 were 28 percent more likely to be diagnosed with inflammatory bowel disease, those aged 40 to 60 were 48 percent more likely, and those over 60-year-olds are 47 percent more likely.

The risk of developing Crohn’s disease from antibiotics was slightly higher than that of ulcerative colitis. The risk increased when more antibiotics were taken: each course of antibiotics increased the risk by an additional 11, 15 or 14 percent, depending on the age group. People who had been prescribed five or more courses of antibiotics were up to twice as likely to have inflammatory bowel disease.

This was observed most frequently with nitroimidazoles and fluoroquinolones. These are broad-spectrum antibiotics that are used, among other things, to treat intestinal infections. They target many different bacteria and not just specific pathogens. Inflammatory bowel disease has also been reported with narrow-spectrum penicillins, but to a much lesser extent. This supports the assumption that changes in the intestinal flora might play a key role in the development of inflammatory bowel diseases. The research team sees these results as further evidence that antibiotics should be used with caution and as specifically as possible.

Which: DOI 10.1136/gutjnl-2022-327845