Frequent use of antibiotics shows link with IBD

Frequent use of antibiotics may increase the risk of inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, in people aged 40 and older, according to the results of a study published in Intestine.

The results show that the risk is cumulative and maximum 1 to 2 years after the use of antibiotics targeting intestinal infections.

Previous evidence has suggested that environmental factors may contribute to the development of IBD, with one factor associated with younger people being the use of antibiotics. However, previously it was unclear if the associate applied to older people.

Investigators used national medical data from 2000 to 2018 for Danish citizens aged 10 or older who have not been diagnosed with IBD. They wanted to determine whether the dosage and timing of antibiotics were important factors for the development of IBD, as well as whether they varied by type of antibiotic and IBD.

More than 6.1 million people were included in the study, of which 5.5 million prescribed at least 1 antibiotic treatment between 2000 and 2018.

During this period, approximately 16,881 new cases of Crohn’s disease and 36,017 new cases of ulcerative colitis were diagnosed.

Overall, compared to no antibiotic use, these drugs were associated with a high risk of IBD, regardless of age. However, the investigators found that older age was associated with the highest risk.

People aged 10-40 years older were 28% more likely to be diagnosed with IBD, while those aged 40-60 were 48% more likely to be diagnosed. The investigators also found that around 47% of people aged 60 or over were more susceptible.

The risks were slightly higher for Crohn’s disease compared to ulcerative colitis at 40%, 62% and 51%, respectively. The risk appeared to be cumulative, with each subsequent course of antibiotics adding an additional risk of 11%, 15%, and 14%, respectively.

The highest risk was seen in people who were prescribed 5 or more courses of antibiotics, with a 69% increased risk for people aged 10-40, double the risk for those aged 40 at age 60 and a 95% increased risk for those aged 60 and over.

The investigators also determined that timing was important, with the highest risk of IBD occurring approximately 1 to 2 years after antibiotic exposure, with each subsequent year associated with a lower risk.

Among 10 to 40 year olds, the risk of IBD was 40% higher 1 to 2 years after taking antibiotics compared to 13% 4 to 5 years later. For people aged 40 to 60, the risk was 66% and 21%, respectively, and those aged 60, 63% and 22%, respectively.

The highest risk of IBD was associated with fluoroquinolones and nitroimidazoles, broad-spectrum antibiotics typically used to treat intestinal infections. Nitrofurantoin was the only type of antibiotic not associated with IBD risk at any age.

Additionally, narrow-spectrum penicillin was associated with IBD, but to a much lesser extent.

The available information did not include what the drugs were used for or how many of them the patients were taking, investigators said.

Reference

Frequent use of antibiotics may increase the risk of inflammatory bowel disease in people over 40. Eurek alert. Press release. January 9, 2023. Accessed January 10, 2023. https://www.eurekalert.org/news-releases/975780