People over 40 years of age should seriously assess their consumption of antibiotics; and not due to the already known risk of multi-resistance to these drugs, but rather, according to a study published in “Gut”, their regular use may increase the risk of inflammatory bowel disease (Crohn’s disease and ulcerative colitis).
Furthermore, the risk appears to be cumulative and greatest between 1 and 2 years after use and for antibiotics that target intestinal infections.
Growing evidence suggests that environmental factors are probably involved in the development of inflammatory bowel disease (EII).
There are about 7 million people in the world with some type of inflammatory bowel disease, and this number is expected to increase over the next decade.
And one of the factors associated with IBD risk in younger people is antibiotic use, although it’s not clear whether this association might also apply in older people.
In this new work, medical data from 2000 to 2018 has been analyzed for Danish citizens aged 10 and over who had not been diagnosed with IBD.
The researchers wanted to know specifically whether the timing and dose of the antibiotic might be important for the development of IBD, and whether this varied by IBD and type of antibiotic.
More than 6.1 millionpeople were included in the study, just over half of whom were women. In total, 5.5 million (91%) were prescribed at least one course of antibiotics between 2000 and 2018.
During this period, 36,017 new cases of ulcerative colitis and 16,881 new cases of Crohn’s disease were diagnosed.
Overall, compared with those who had never taken antibiotics, their use was associated with a higher risk of developing IBD, regardless of age. But the older the age, the greater the risk.
Thus, people between the ages of 10 and 40 were 28% more likely to be diagnosed with IBD; while those between 40 and 60 years old were 48% more likely to do so, a figure that reached 47% in those over 60 years of age.
The risks were slightly higher for Crohn’s disease than for ulcerative colitis.
The highest risk of all was seen among those who received 5 or more courses of antibiotics: 69% increased risk for people aged 10 to 40 years; a doubling of risk for people ages 40 to 60; and an elevated risk of 95% for those over 60 years of age.
Timing also seemed to play a role, with the highest IBD risk occurring 1 to 2 years after antibiotic exposure, with each subsequent year thereafter associated with a decreased risk.
Regarding the type of antibiotic, the highest risk of IBD was associated with the nitroimidazoles and fluoroquinolones, which are often used to treat intestinal infections. These are known as broad-spectrum antibiotics because they indiscriminately target all microbes, not just disease-causing ones.
Narrow-spectrum penicillins were also associated with IBD, although to a much lesser extent. This adds weight to the idea that changes in the gut microbiome may play a key role, and that many antibiotics have the potential to alter the composition of microbes in the gut.
Limiting antibiotic intake can not only help curb antibiotic resistance, but can also help reduce the risk of IBD
However, the researchers caution that this is an observational study and, as such, cannot establish cause. There was also no information available on what the drugs were for or how many of them the patients actually took.
But there are some plausible biological explanations for the findings, they suggest, highlighting the natural decline in both resilience and microbial variety in the gut microbiome associated with ageing, which is likely to be exacerbated by antibiotic use.
Limiting antibiotic intake may not only help curb antibiotic resistance, but may also help reduce the risk of IBD, they venture.
“The association between exposure to antibiotics and the development of IBD underscores the importance of administration of antibiotics as a public health measure and suggests that the gastrointestinal microbiome is an important factor in the development of IBD, particularly among older adults,” they conclude.