Much has been said recently (in both science and popular media) about the importance of a healthy microbiome–referring to the microscopic community of bacteria, both good and bad, that we host in our bodies throughout our lives.

Babies are born with an immature immune system and a nearly sterile gut. Programming of their systemic immunity begins soon after birth and is strongly influenced by the multitude of bacteria that colonize the gut in their first days and weeks to form the body’s microbiota.

The colon is the largest participant in the body’s immune system. Nearly sterile when a baby is born, the gut quickly is colonized by a multitude of bacteria that make up its microbiota.