Study tries to give C-section babies mom's germs they missed

WASHINGTON - Sharing bacteria in the operating room normally is a no-no, but in a novel experiment, researchers are giving babies born by C-section a dose of presumably protective germs from the mother's birth canal.

We share our bodies with microbes - on the skin, in the mouth, in the gut - that help keep us healthy, a community, or microbiome, that starts forming at birth. Usually, a vaginal birth marks babies' first massive exposure to the bacteria. But babies born by C-section miss out on those particular bugs, something many scientists suspect could have consequences later in life.

Monday, researchers reported the first hint that it's possible to at least partially restore mom's missing microbes to babies born surgically, simply by swabbing those infants with their mother's vaginal fluid within two minutes of birth.

"What we are going to show is how babies assemble their microbiome," said microbiologist Maria Gloria Dominguez-Bello of New York University, who led the pilot study published in the journal Nature Medicine. "Do C-section babies ever catch up?"

Far more research is needed to prove if the technique really works - or makes a difference in babies' health.

This first-step attempt to manipulate birth microbes was very small, comparing seven babies born vaginally with 11 born by scheduled C-section, four of whom got that dose of the mother's bacteria. Over the next month, researchers took more than 1,500 samples of different body sites to see how the infants' own microbiomes were developing.

The specially exposed C-section babies developed microbial neighborhoods that were more similar to vaginally born infants than to the other infants born surgically, Dominguez-Bello reported. In particular, the swabbed babies harbored more of two bacteria species - Lactobacillus and Bacteroides - that are thought to play a role in training the immune system, and that were nearly absent in the untreated C-section babies.

The bigger question is not just how the bugs affect early microbiome development but whether that translates to better health years later. For example, previous studies have suggested babies born by C-section have a higher risk of developing asthma, allergies and certain other health conditions, and no one knows why.