The rise in antibiotic-resistant infections caused by “superbugs” has been widely reported in recent years – most of it due to the overuse of antibiotic medications. Last year, a report from the United Nations warned that if the issue was not addressed, antimicrobial resistance could result in 10 million deaths a year around the world by 2050.
This week, a study published in the journal Nature Microbiology finds yet another reason to be concerned: antibiotics appear to interfere with the function of the intestinal tract’s beneficial gut flora, increasing susceptibility to colitis. Furthermore, this susceptibility can be passed by a mother on to her offspring who may never have been exposed to antibiotics at all.
In the study, healthy pregnant lab mice were divided into two groups: one was given a culture of healthy gut flora, or “microbiome,” while the other was given a microbiome that had been exposed to antibiotics. What they discovered has grave implications: the mice pups born to mothers in the antibiotic group had inherited the altered microbiome.
As part of the study, scientists looked at mice that had been genetically engineered to be predisposed to colitis. By five months of age, young mice born to mothers with antibiotic-treated microbiomes had significantly worse cases of colitis than those born to untreated mothers.
This study, carried out at New York University’s Langone Medical Center, is not the first to find a link between antibiotics and an increased risk of intestinal disease. A study published in Pediatrics in October 2012 determined that childhood exposure to antibiotics could make a young person more likely to suffer from irritable bowel syndrome (IBD), although this risk generally decreased with age.
The current study is the first to find health dangers beyond antimicrobial resistance, however. Dr. Martin Blaser, one of the study’s co-authors, pointed out, “The pups never [received] antibiotics and their mothers never [received] antibiotics.” He adds, “A lot of pregnant women are taking antibiotics, and a lot of teen girls are taking antibiotics…we are concerned that it could have an effect on the next generation.”
Granted, mice are not humans, and approximately 10 percent of IBD cases are genetic. However, the results of the Langone study suggests that antibiotics could play a part in the other 90%. Blaser says he has no problem with antibiotics in general, but warns that they must be used far more judiciously. “I think that we are going to find out more and more that [exposure to antimicrobial medications] has a disease cost.”