We’ve talked extensively on the blog about antibiotics and the both positive and negative effects they can have on people’s health. Marty Blaser, professor at NYU School of Medicine and the world leader in studying antibiotics and their role on obesity and other health effects, published a study in Nature Communications last week on the effects that antibiotics can have if administered early in life.
Dr. Blaser and his colleagues used mice to administer various antibiotic regimes that included amoxicillin and macrolides. They provided the mice three antibiotic treatments, called pulsed antibiotic treatment (PAT), to the mice to mimic frequent antibiotic use in children. They found that the mice that were given the PAT saw short-term increases in weight as well as bone growth, specifically increased bone growth after amoxicillin treatment and increased fat after tylosin (macrolide) treatment.
The scientists also saw long-term alterations in the gut microbiota of mice given a PAT regime. Mice that were given antibiotics had decreased microbial diversity different proportions of bacteria compared to control mice. Surprisingly, the change in microbiome persisted until the time of the mouses' deaths, 120 days after the last antibiotic treatment. They also saw differing gene expression in the mice that were given pulsed antibiotic treatments. These two results give evidence that antibiotic use is leading to permanent physiological changes in the body.
Dr. Blaser has long been telling us that the early stages of life, the time when we most frequently administer antibioitics, is critical to development and that antibiotic use can drastically alter this development. This study supports other research by Dr. Blaser and colleagues that has shown that antibiotic use in early life predisposes us to obesity.
While we know antibiotic use can have these negative long-term effects, they are still essential and are life-saving drugs for when we have bacterial infections. The authors state that this work and other work showing the negative effects antibiotics can have should lead to increased awareness as well as a re-examination of policies and guidelines to antibiotic use in humans.