Early Antibiotic Exposure May Lead to Inflammatory Bowel Disease

Childhood exposure to penicillin, tetracyclines, and other common antibiotics which kill anaerobic bacteria found in the gut was associated with an overall 84% elevated risk of developing inflammatory bowel disease (IBD), especially when exposure occurred in the first year of life.

Researchers hypothesized that changes in the levels of gut microbiota, whether in pathogenic or protective bacteria, was responsible for inflammation in children with IBD. 

In a retroactive cohort study, researchers used data from from The Health Improvement Network registry of 1,072,426 children without IBD in the United Kingdom.  Children were followed for at least 2 years between 1994 and 2009, during which time the disease developed in 0.07%. 

Of the participants, 58% had a history of exposure to antianaerobic antibiotic, including penicillin, amoxicillin, ampicillin, penicillin/beta-lactamase inhibitor combinations, tetracyclines, clindamycin, metronidazole, cefoxitin, carbapenems, and oral vancomycin.

Adjusted hazar ratios with antianaerobic exposure versus no exposure were 5.51 for exposure before 1 year of age (95% CI 1.66 to 18.28), 2.62 for exposure by 5 years of age (95% CI 1.61 to 4.25), and 1.57 for exposure by 15 years of age (95% CI 1.35 to 1.84).

Risk was increased by 6% with each course of antibiotics, and by 1% for each additional week of exposure.

Only 1.6% of the prescribed antibiotics were to treat gastrointestinal infections.  The exclusion of data from these cases did not alter the study’s results. 

"Many unanswered questions remain…such as whether specific difficult-to-culture organisms could play roles in either IBD pathogenesis or protection against IBD, and whether alteration of flora through antibiotic exposure alters the immune system directly," researchers concluded. 

-Michael Potts