When we are born, we go through our mothers’ vaginal canals (our birth canal) and are exposed to our mother’s microbiome. We suck on our parent’s skin. We then are nursed by our mothers and with that, are exposed to our mother’s skin flora and receive bacteria, antibodies and nutrients that our mother’s milk possesses. Soon after birth, the newborn’s gut is rapidly populated with bacterial that have been shown to contribute to creation and maintenance of the epithelial barrier, aid in gut hemostasis and formation of blood vessels. We know that those bacterial are responsible for creation of host immune function.[i] We then crawl on the floor and suck on our toys. We are exposed to other people, our pets and our plants, all of which are covered in bacteria and nourish our gut. We go outside and are exposed to dirt with all of its valuable bugs. We start eating plants and animals all of which cause our gut to change and evolve. Our intestine becomes strong and hardy and the intestinal barrier becomes strong. Somewhere along the way, things have changed as explained by the “hygiene hypothesis.” We clean everything with antibacterial soaps and alcohol based hand sanitizers which kill the bugs that live on our hands. We over-wash and over-sanitize not allowing the dirt from the earth to get into our bodies. Over time, we are seeing smaller families, improvements in household facilities and better hygiene and with that, we are seeing more allergic illnesses and inflammatory conditions. Don’t be afraid of them.[ii]
[i] Hooper LV, Gordon JI. Commensal host-bacterial relationships in the gut. Science 292:1115–1118
[ii] Strachan DP. Hay fever, hygiene, and household size. BMJ 1989; 299:1259– 1260.