The human body is home to literally trillions of bacteria cells—most of which reside in the gut, where they play a vital role in healthy digestive and immune function. But just where do they come from? We often hear that babies get their first dose of bacteria in the birth canal during delivery, but results of a new study offer a surprising revelation: that a newborn’s first exposure may happen even earlier.
Published last month in the journal Science Translational Medicine, the study suggests babies come into contact with a “small but diverse amount of bacteria” in the placenta—an organ that begins to develop shortly after fertilization and nourishes the developing fetus throughout pregnancy. This is interesting mainly because the mother’s womb was typically believed to be a sterile environment, but now there is evidence of a pre-existing bacterial community within the placenta—and that’s not all.
In looking at more than 300 samples from a combination of vaginal, cesarean, full-term and pre-term births, scientists noticed that the bacteria found in the placentas—roughly a few hundred different types—didn’t look like the bacteria found in the stomachs of the newborn babies. Rather, they resembled the bacterial community in the mouth of the mother. This led scientists to conclude that the mother’s oral bacteria could reach the developing baby via the bloodstream, and to stress the importance of oral health during pregnancy and even before.
So how does this study change things? Essentially, instead of acquiring their first dose of healthy microbes during the birthing process, which was widely thought to be the case, this new information suggests babies may come into contact with those microbes much earlier (i.e. in the placenta)—and that those bacteria may actually play a role in healthy fetal development.
Regardless of when newborns receive their first microbes, supplying additional beneficial bacteria throughout the early years may help promote digestive and immune health—since up to 80 percent of the immune system can be found in the gut. Keep in mind that children encounter constant challenges to their immune and digestive systems while at school and play, and good bacteria can also be depleted by an unhealthy diet and certain medications.‡ A daily probiotic supplement may help promote a healthy balance of intestinal flora to support digestion, and they are considered a safe and gentle way to help support the immune system.‡