In the Media

Is a person’s future health shaped by microorganisms encountered early in life?

By Sarah Deweerdt

Within a few weeks of being born, a baby is host to a community of billions of bacteria, viruses and fungi — most of which are found in the gut — that can shape many aspects of health. How that community, or microbiota, assembles is a matter of debate: some researchers have begun to question the dogma that the womb is a sterile environment. Yet it’s clear that birth sets off a radical transformation of the infant gut.

“It’s an incredible ecological event,” says Phillip Tarr, a paediatric gastroenterologist at Washington University in St. Louis, Missouri. Colonization of the gut begins in earnest when a baby encounters microorganisms from its mother’s vagina during birth.