Antibiotics may increase bowel disease risk in over-40s

Frequent use of antibiotics may increase the risk of inflammatory bowel disease (IBD) among the over 40s, new research suggests.

The risk appears to be cumulative, peaking 1-2 years after use and for those antibiotics targeting gut infections.

Researchers from New York University and Aalborg University in Denmark analysed medical data from 2000 to 2018 for Danish citizens aged 10 and above who had not been diagnosed with IBD.

The scientists wanted to know if the timing and dose of antibiotic was important for the development of IBD, and whether this varied by IBD and antibiotic type.

More than 6 million people were included in the study, just over half of whom were female.

A total of 5.5 million (91 per cent) were prescribed at least one course of antibiotics between 2000 and 2018.

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

Overall, in comparison to no antibiotic use, the drugs was associated with a higher risk of developing IBD, regardless of age.

However, older age was associated with the highest risk.

Those aged 10-40 were 28 per cent more likely to be diagnosed with IBD; 40- 60 year olds were 48 per cent more likely to do so, while the over 60s were 47 per cent more likely to do so.

The authors wrote:

“In our study, we see antibiotic use was associated with a higher risk of developing IBD among older adults as compared with younger individuals.

“We also observed an increased risk for developing IBD 4–5 years after exposure.

“This may be the result of persisting changes in the microbial environment as a result of antibiotic use, which ultimately contribute to the development of IBD.”