Why is this suddenly BIG news? They've known this for years. It has something to do with early exposure to (farm) animals, dirt, pollens, etc. Maybe they needed an official study to prove it or something.
This. It has been known for years, and it is so easily understandable. If you grow up in the dirt, your body will be able to defend yourself. If you grow up in a bacteria free house where mommy desinfects everything and everyone, when you get out you will die.