WIKIMEDIA, JEAN HOUSENPopular thinking has held that as a baby works his way through a birth canal teeming with microorganisms, his body is colonized with its first commensal bacteria. But a new study shows that a bevy of microbes exist in the womb.
The findings, published today (May 21) in Science Translational Medicine, add to a growing body of literature suggesting that tissues once thought to be germ-free are crawling with microbes, and that babies’ introduction to the microbial world comes from multiple maternal sources.
“[It’s an] interesting study that continues to build the snowball that no tissue in the human body is sterile, including reproductive tissues and, for that matter, the unborn child,” Seth Bordenstein, a biologist at Vanderbilt University who was not involved in the work, said in an e-mail to The Scientist.
Hints that the uterine environment harbors bacteria began to emerge several years ago. In 2008, for instance, Juan Miguel Rodríguez’s group at the Complutense University of Madrid in Spain inoculated pregnant mice with ...