Most of the time we think of gastrointestinal health as something to pay attention to as we age or when we start seeing problems with our health. However, more and more research is coming out showing that our gastrointestinal health starts in our development, prenatally and throughout our infancy. Babies in utero are going through a complex process as they develop their immune system. For instance, we now know that vernix, the thick, waxy substance covering a baby in the womb, is not just for protection of the skin from soaking in amniotic fluid.