We’ve all heard by now that over zealous use of antibiotics – both prescriptions for humans and low doses in animal feed – is giving rise to antibiotic-resistant strains of bacteria. But a potentially bigger issue is the changes in our entire microbial community brought on by antibiotics. The scorched earth strategy of antibiotics not only wipes out the target pathogen(s), but cripples and shifts entire gut communities from the friendly fire. Researchers now think early childhood exposure to antibiotics may be associated with development of the lifelong autoimmune condition of inflammatory bowel condition (IBD).
Like so many human-made diseases, the incidence of childhood IBD is on the rise – nearly doubling in the last decade alone. The leading hypothesis of IBD pathogenesis points to bacteria: either an increase in pathogenic bugs or a decrease in protective bacteria. In either case – or a combination of the two maybe – inflammation occurs.
Using electronic medical records in the United Kingdom collected from 1994 to 2009, researchers looked at antibiotic use among an astounding 1,072,426 British children. They wanted to know which antibiotics (e.g., penicillin, amoxicillin, clindamycin, etc.) the kids received, and at what age, how often, how long, and whether there was an association between antibiotic exposure and IBD development later on. Below is what they found.
The following illustration plots the proportion of subjects who developed of IBD according to age and antibiotic exposure. Among the million plus children in the study group, 57.7% were exposed to at least one antibiotic. As the graph illustrates, the proportion of subjects who developed IBD increases as the exposure to antibiotics increase.
Interestingly, exposure to broad-spectrum penicillin’s and cephalosporins were associated with IBD development among the children, “whereas macrolide, sulfonamide, and tetracycline exposure were not.”
The researchers also noted that children living in extreme social deprivation (that is, poor kids) were much less likely to develop IBD. This finding suggests that where you grow up and with whom matters. That is, poorer populations are more likely to live amongst more vermin and have slightly different hygiene practices – all of which provide early and protective education of the immune system. Said differently, early childhood exposure to the myriad of natures many microbes and parasites educates the immune system – as it has done throughout human evolution – to recognize friend from foe and not to twitch and overreact to shadows. Remove the dirt, filth, and microorganisms of our ancestral past and replace it with wet wipes, triple-washed produce, and too many antibiotics, you invite autoimmune diseases like IBD. The following study suggests that antibiotic exposure could be removing some protective organisms among the study population and that well-to-do children may be at a disadvantage from the get go.
As the researchers note, nearly half of the estimated 49 million antibiotic pediatric prescriptions in the U.S. every year are for penicillin. The UK data suggests that these prescriptions may result in thousands of new IBD cases each year. Making matters even worse, Martin Blaser at New York University notes that the average child in the U.S. will receive 10-20 courses of antibiotics by the time he or she is 18 years old. Given what appears by any measure an epidemic of autoimmune disease in the developed world, we might want to spend a little more time nurturing and stabilizing our gut microbial ecosystem through more thoughtful use of antibiotics (more targeted and less broad-spectrum) and adopting dietary strategies that promote balance. Time we honored thy symbionts.