Our microbiota is acquired at birth. Before a baby is born, the intestinal tract is sterile. [1]  Starting with the birth process and exposure to the mother’s flora, the infant gut is colonized with microbes and its immature immune system starts to develop as it comes in contact with dietary and microbial antigens in the gut. The growing and evolving microbiota has a significant impact on the baby’s developing immune system
Everyone knows that our immune system is what keeps us healthy despite the continual onslaught of potential invaders that bombard us each day. Where is this mysterious invisible thing we call our immune system? Surprisingly, 70-80% of immune cells reside in our gut, that long meandering intestinal system that starts with the mouth and travels down to the end of the large intestine. [2] 
Evidence is mounting that an early and intimate interaction exists between the GI microbiota and immune defenses. [3] This relationship is key for babies to develop a healthy functioning immune system. Recent studies have suggested that lack of contact with harmless microbes early in life is partially responsible for a less robust immune system later in life. [3]
One old adage says that we have to eat a peck of dirt before we die. However, to take the peck of dirt literally means we are also exposed to non-beneficial organisms, as well. The best case scenario is to shift the balance of power toward a healthy immune response by adding beneficial bacteria, like L. reuteri, to your child’s daily regimen. The whole field of probiotics is an application of the knowledge we’ve gained from studying our microbiota and using it to promote better health.


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