Our bodies have evolved in relationship to the environment for three billion years. We have developed symbiotic and synergistic relationships with other living organisms. Our digestive tracts are a great example of this relationship, since the intestinal tract is lined with trillions of bacteria and yeasts that are totally foreign (non-human living cells) and yet, collectively they form an organ that is vital to the healthy function of your body, as without them you wouldn't be alive at all.

We all have two to four pounds of these foreign cells, mostly lining our digestive tract as well as other surface areas that interact with the ...