Are antibiotics a contributory factor to the rise in allergic and other Chronic Inflammatory Diseases?

A key strategy being used to tackle the global problem of antibiotic resistance is the control of antibiotic prescribing. If, as seems likely, antibiotic overprescribing is also a causative factor in the rising levels of inflammatory diseases such as asthma, eczema, hay fever and so on, this provides a further argument which could be used to discourage parents from seeking antibiotic treatments for their children for minor infections, or for infections which are viral in origin.

This report reviews the epidemiological studies (more than 40) which have evaluated the possible link between antibiotic usage and the development, primarily of asthma, but also eczema, cow’s milk allergy and irritable bowel disease (IBD). Although there is still much concern and discussion that there may have been some overestimation of the association, due to confounding factors such as reverse causation, many or most workers now agree that there is strong evidence that antibiotic usage during pregnancy or the neonatal period, is a contributory factor in the development of these diseases, although the extent of this association is not clear, and certainly other factors are also involved.

A potential explanation for this effect is that antibiotics alter the gut microbiota, which in turn affect the maturing immune system in a way that promotes allergic disease development. This concept has its origins within the so-called “hygiene hypothesis. The latest, and more plausible, thinking is that particularly during early development, the human body requires exposure to a broad range of microbes, but that these are the largely non harmful microbes which make up the microbiota of our human (gut, skin, etc.), animal and natural environments.

The report also reviews animal studies, which increasingly support the concept of a link between early-life antibiotic use and development of allergic diseases and are beginning to reveal the mechanisms by which this can occur.