Research performed by a team at the NYU Grossman School of Medicine suggests that antibiotic use may cause older adults to develop inflammatory bowel disease.
The new study analysed 2.3 million patient records, discovering that the risk of developing inflammatory bowel disease for people aged 60 and over correlates with the number of antibiotics they are prescribed. The findings may explain the rise in Crohn’s disease and ulcerative colitis cases among older adults.
Adam S. Faye, MD, MS, lead researcher on the study and assistant professor of medicine and population health at NYU Grossman School of Medicine, commented: “In older adults, we think that environmental factors are more important than genetics. When you look at younger patients with new diagnoses of Crohn’s disease and ulcerative colitis, there’s generally a strong family history. But that is not the case in older adults, so it’s really something in the environment that is triggering it.”
How was the study conducted?
The researchers utilised Denmark’s national database to perform their study, which comprises medical records of all residents in the country. The team examined prescription records of people aged 60 and over who were diagnosed with inflammatory bowel disease between 2000 and 2018, identifying how many courses of antibiotics they were prescribed, the time they were prescribed in relation to their inflammatory bowel disease diagnosis, and the types in antibiotics used.
How do antibiotics influence inflammatory bowel disease?
The results signified that antibiotic use was associated with higher rates of inflammatory bowel disease, with the rate significantly increasing with each course of the treatment. Patients after one course of antibiotics were 27% more likely to be diagnosed with inflammatory bowel disease versus those with no antibiotic use.
This risk was significantly exacerbated with each additional course. After two courses, the risk increased by 55%, three courses increased the risk by 67%, and four courses elevated the risk by 96%. Worryingly, older adults that had five or more courses of antibiotics were 236% more likely to be diagnosed with inflammatory bowel disease than those with no history of antibiotic use in the last five years.
New diagnoses were most common in the first two years following antibiotic use, although the increased risk persisted for five years. The team found that all types of antibiotics caused this effect, except for a drug prescribed to treat urinary tract infections called nitrofurantoin. The most likely antibiotics to cause inflammatory bowel disease were those usually prescribed for gastrointestinal infections. The researchers did not include prescriptions less than a year before diagnosis to mitigate the chance that the prescription had been for symptoms of an undiagnosed gastrointestinal disease.
Dr Faye concluded: “The study has implications for diagnosing older adults with new gastroenterological symptoms. Inflammatory bowel disease, which can easily be overlooked in this age group, should be considered, especially when there’s a history of antibiotic prescriptions.
“Antibiotic stewardship is important, but avoiding antibiotics at all costs is not the right answer either. If you’re not sure what you are treating, I would be cautious. If patients are coming in with clear infections, and they need antibiotics, they should not be withheld because of these findings.”