Antibiotics Given to Babies May Change Their Gut Microbes for Years

Babies born by caesarean section, as well as those given antibiotics early in life, have a different balance of gut microbes than other babies, two new studies show. These differences could put them at higher risk for various health problems in childhood, including asthma, type 1 diabetes, and perhaps even autism. By the time children are 3 years old, their microbiomes are largely stable, said Dr. Ramnik Xavier, a lead author on one of two related studies published Wednesday in Science Translational Medicine. So what happens early in life can have long-term implications for health.

His study followed 39 Finnish children from birth to age three, while the other study, from New York University, tracked 43 youngsters in New York City. Families in both places delivered the contents of dirty diapers to clinics, which stored them in freezers to keep the fecal microbes intact until scientists could extract DNA and identify the thousands of bacterial species hiding inside.

Both studies showed that kids prescribed antibiotics in their first few years had a different balance of microbes than those who did not need the medications. They also found different cohorts in children born by C-section compared to vaginal delivery.
Earlier studies had suggested the same results, but the new research analyzed the microbiome more deeply and followed the same children over a period of time, said Xavier, who is also an affiliate of the Broad Institute. The microbiomes of children born by C-section look less mature than those delivered vaginally, said Dr. Martin Blaser, a professor at NYU who headed the second study...