Over 40s at greater risk of IBD after several doses of antibiotics

PEOPLE over the age of 40 who take antibiotics are nearly 50 per cent more likely to develop Crohn’s disease or colitis, a study has found.

Irritable bowel disease (IBD) includes both the chronic inflammatory conditions with more than 500,000 sufferers in the UK. Data from more than six million people in Denmark, followed for more than a decade, found that taking antibiotics was linked to an increase in an individual’s risk of IBD.

The effect was seen for all age groups, but was most pronounced in the over40s. If a person between the age of 40 and 60 has taken antibiotics in the last five years they are 48 per cent more at risk of IBD. For over-60s, the figure is 47 per cent, the study found. But the scientists also discovered the effect to be cumulative. A 40-year-old who has had one course of antibiotics has a 27 per cent increased risk of developing Crohn’s or colitis but this increases by about 15 per cent for every subsequent dose. The researchers from New York University and Aalborg University in Denmark found that a 40-year-old who has been prescribed antibiotics five or more times is more than twice as likely to get IBD than someone who has never been on them. Nine out of ten people in the study were prescribed antibiotics at some point and the team recorded more than 36,000 cases of colitis and almost 17,000 new cases of Crohn’s.

Dr Laila Tata, co-author of the study said the increased risk of IBD after antibiotics “could be related to changes in gut flora”. IBD is partly controlled by genetics but lifestyle and environmental factors such as diet and smoking can also alter a person’s individual risk.

“There’s definitely differences in genetic susceptibility,” Dr Tata added. “It’s been found to be diagnosed increasingly in line with urbanisation and Westernisation which indicates these factors are slightly increasing the diagnosis rate. However, there are also a lot of people who may be living with it without having it diagnosed.”

‘Irritable bowel disease is increasingly diagnosed in line with urbanisation and Westernisation’