Gut bacterial balance during pregnancy—especially toward the end of pregnancy—is crucial because when a baby is born through the birth canal, the bacteria colonizing the mother are transferred to the infant where they begin to colonize the digestive tract. So, when a mother has a healthy balance of gut bacteria, baby will too, and vice versa.

A recent study by the Yakult Central Institute for Microbial Research tested this concept. They isolated bacterial strains from pregnant women, and then later from the infants they gave birth to, and found the exact same Bifidobacterium strains in the stool of the infants. The scientists isolated over 2,500 strains and found five strains that were consistently shared between mother and baby: B. adolescentis, B. bifidum, B. catenulatum, B. longum, and B. pseudocatenulatum.

Dr. Kenji Oishi, lead researcher, concluded that a mother’s intestinal balance “seems to be a positive contribution towards the development of the newborn’s intestinal microbiota.” Of course, this study serves as yet more proof that maintaining gut balance during pregnancy is important, given what we know about how the establishment of gut bacteria during early life sets the stage for long-term health.

If you or someone you know is pregnant and you haven’t thought about balancing your gut flora, think again. It’s more important than you may have realized.