A study published today on the effects of antibiotic treatment in early-life shows it can result in long lasting changes in the gut microbiome as well as increased weight and bone growth in mice.
The authors of the study, led by Martin Blaser at NYU Langone Medical Center, had published a paper last year on the effects of low doses of antibiotics in early-life (like the antibiotic treatment given to farm animals for growth) which showed profound changes in the mouse gut microbiome. They showed this can lead to weight gain later in life especially in combination with a high fat diet. Most human infants, however, don’t receive chronic low doses of antibiotics. Rather, they receive pulsed high doses of antibiotics. If low doses can cause such big changes, what would these high doses do?
The authors set out to answer this question by giving antibiotics to mice in the second, fourth, and fifth weeks after birth. After 23 weeks, they studied the gut microbiome of the mice. The mice with the antibiotic treatment had less diversity in their microbiota than the control group even months after the treatment. Blaser says, "There are really long-term, probably permanent effects on the microbiome from antibiotics. This suggests that perhaps we should be cautious in prescribing antibiotics for babies up to 2 or 3 years."
Y.R. Nobel et al. “Metabolic and metagenomic outcomes from early-life pulsed antibiotic treatment,” Nature Communications, DOI: 10.1038/ncomms8486, 2015.