According to a study published online in the journal Gut, antibiotic usage may raise the risk of inflammatory bowel disease (Crohn’s disease and ulcerative colitis) in adults over 40. According to the data, the risk appears to be cumulative and is greatest 1-2 years after usage and for antibiotics used to treat gastrointestinal infections. Environmental variables are likely involved in the development of inflammatory bowel disease, according to mounting research (IBD). According to the researchers, close to 7 million people worldwide have the illness, with that figure predicted to climb over the next decade.
The use of antibiotics is one factor related with IBD risk in younger individuals, although it is unclear if this relationship applies to older persons. To go deeper, the researchers examined national medical data from 2000 to 2018 for Danish people aged 10 and above who had not been diagnosed with IBD.
They were particularly interested in learning if the time and dose of antibiotics were relevant in the development of IBD, and whether this varied by IBD and antibiotic type. The survey comprised approximately 6.1 million people, with women accounting for slightly more than half of the participants. Between 2000 and 2018, 5.5 million people (91%) were administered at least one course of antibiotics.
Approximately 36,017 new instances of ulcerative colitis and 16,881 new cases of Crohn’s disease were identified during this time period. Overall, usage of these medicines was related with a greater risk of developing IBD, regardless of age, as compared to no use. However, greater age was related with the greatest risk.
Those aged 10-40 were 28% more likely to be diagnosed with IBD, those aged 40-60 were 48% more probable, and those over 60 were 47% more likely. Crohn’s disease had a somewhat greater risk than ulcerative colitis: 40% among 10-40 year olds, 62% among 40-60 year olds, and 51% among those over 60.
The danger appeared to be cumulative, with each consecutive course increasing the risk by 11%, 15%, and 14%, respectively, depending on age band. The biggest risk was reported among individuals administered 5 or more courses of antibiotics: a 69% increase in risk for 10-40 year olds, a doubling in risk for 40-60 year olds, and a 95% increase in risk for those over 60.
Timing appeared to be important as well, with the largest risk for IBD occurring 1-2 years following antibiotic exposure, and each subsequent year linked with a decrease in risk.
IBD risk was 40% greater 1-2 years after using antibiotics among 10-40 year olds, compared to 13% 4-5 years later. The similar percentages for 40-60 year olds were 66% vs 21%, and 63% vs 22% for those over 60. In terms of antibiotic class, nitroimidazoles and fluoroquinolones, which are often used to treat gut infections, were related with the highest risk of IBD. Broad spectrum antibiotics are so named because they target all bacteria, not only those that cause illness. Nitrofurantoin was the only antibiotic that was not linked to an increased risk of IBD at any age.
Narrow spectrum penicillins were also linked to IBD, but to a lesser extent. This lends credence to the idea that alterations in the gut microbiome may play an important role, and that many medications have the ability to alter the composition of microorganisms in the gut. Because this is an observational research, it cannot determine causality.
The researchers also remark that there was no information available on what the medications were for or how many of them patients really consumed. However, they provide some reasonable scientific reasons for the findings, noting the natural decline in both the resilience and diversity of microorganisms in the gut microbiome associated with age, which antibiotic use is expected to exacerbate.
“Furthermore, with repeated antibiotic treatments, these alterations might become more prominent, eventually restricting regeneration of the gut microbiota,” they write.
Limiting antibiotic prescriptions may assist to reduce not just antibiotic resistance but also the risk of IBD, scientists speculate.
“The connection between antibiotic exposure and the development of IBD emphasises the need of antibiotic stewardship as a public health strategy, and implies that the gut microbiota is a significant determinant in the development of IBD, particularly among older persons,” they write.