Resources on hyper-sterility vs. risk of infection

In this post I'm linking to two resources that seem to differ widely but touch on the same root topic: have some of our modern means of sanitizing and disinfecting our environment caused us unforeseen problems? This is an article about raw milk. The debate is that raw milk contains certain nutrients and flavors that pasteurized milk doesn't, but raw milk can also lead to major infection by microorganisms. Act III of this episode of This American Life tells the story of a man who deliberately infected himself with hookworms to counteract his severe allergies. Once again, the drawbacks of a potential disease agent (in this case hookworms affect the body's iron and protein uptake, potentially leading to anemia) is weighed against its positive effects.