Recent research has shed light on the importance of gut microbiota both during pregnancy and early life. Despite recent research that shows the placenta is not sterile, as previously thought, gut microbiota colonization in the first days and weeks after birth appears to have enormous significance for post-natal life.

How might microorganisms move from one part of the body to another? Let's begin with the womb, where the concept of fetal colonization has rapidly gained acceptance, indicated by meconium and placental microbe studies.