Expert Q&A

Impact of Antibiotic Use on Older-Onset IBD Development

While most individuals with inflammatory bowel disease (IBD) are diagnosed in young adulthood, an increasing incidence of older-onset ulcerative colitis and Crohn disease have been noted in recent years. Some have hypothesized that the increase in older-onset IBD may be due to environmental factors individuals are exposed to throughout their lifetime.

Authors of a population-based cohort study aimed to examine the relationship between one of these potential environmental factors, antibiotic use, and the risk of IBD development in adults aged 60 years or older in Denmark. The study found that higher rates of IBD were associated with each course of antibiotics the participants received; one course was associated with a 27% greater risk while four courses associated with a 96% greater risk.

Lead study author Adam Faye, MD, MS, answered questions about this study and the study implications. Dr Faye is an assistant professor of medicine and population health at New York University’s Grossman School of Medicine.

Consultant360: To begin, what prompted this study? 

Adam Faye, MD, MS: Older-onset IBD seems to be a separate clinical entity from younger-onset IBD, with- different clinical presentation and disease phenotypes. Thus, the risk factors for the development of IBD may be different in older adults vs younger adults. Additionally, older adults less commonly have a family history (or genetic risk) of IBD, suggesting environmental factors may play more of a role in the development of older-onset IBD. As there has only been minimal data looking at antibiotics and the development of older-onset IBD, we wanted to add to what was known. 

Consultant360: Your study found that not only is antibiotic use associated with an increased risk of older-onset IBD, but all antibiotic classes (including those not used to treat gastrointestinal infections) were associated with this disease development. Is this a result that surprised you, or did you anticipate this? 

Dr Faye: We actually found that the majority of antibiotic classes led to the development of older-onset IBD, but found that antibiotics with minimal impact on the intestinal microbiome did not increase the risk of older-onset IBD. For example, Nitrofurantoin, which is often used to treat urinary tract infections, did not increase risk of IBD. We think antibiotics are likely changing both the composition and proportion of microbes in the intestine, and when this homeostatic balance is disturbed, it may increase the risk of developing IBD (our hypothesis at this time given our findings). There is much research going on in this domain to further explore this finding but this would fit with a changing intestinal microbial environment. 

Consultant360: How does the management of ulcerative colitis and Crohn disease differ in older adults vs younger populations? 

Dr Faye: This is a great question. The goal in both older and younger adults is to control ongoing inflammation to limit adverse events. Depending on certain comorbidities and other factors such as shorter life-expectancy, however, goals can shift to prioritize quality of life. Pertaining to treatment, we have the same treatment modalitiesHowever in older adults, there does seem to be a higher risk of adverse events as a result of therapy. Whether this is due to underlying physiologic differences, or a general hesitation to use certain treatment modalities, such as anti-TNF or surgery in older adults, remains unknown. Additionally, with the development of newer biologics that have fewer side-effects, we see that they are more often being used in older adults to limit any potential adverse events. 

Consultant360: Has the relationship between older-onset IBD and any other environmental factors, such as diets high in processed food or exposure to pollution, been studied in the literature? Are there any other environmental exposures that you hypothesize may be associated with this disease development? 

Dr Faye: Great question. This remains to be seen. There have been some studies suggesting [relationships between] diets, tobacco, or pollutionbut none specifically within older adults with IBD. Similarly, there has been some work looking at statins, and because of their anti-inflammatory properties, it's possible they have protective effects particularly in older adults, but this remains to be seen.

Consultant360: What are the next steps for research concerning the relationship between antibiotic use and IBD? 

Dr Faye: The next steps specifically would be to further investigate the hypothesis that our findings are due to changes in the intestinal microbial environment. More globally, we need to investigate other environmental factors as well. 


Faye A, Allin K, Iversen A, et al. Antibiotics as a risk factor for older onset IBD: a population-based cohort study. JCC. 2022;16(1):i056. doi:10.1093/ecco-jcc/jjab232.045

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