The hygiene hypothesis states that children who grow up in meticulously clean, sterile environments never have the chance to develop strong immune responses to their environment. The results… kids of overly clean households are usually the sickest and weakest.
Adaptive immunity is our natural way of learning how to fight illness from being exposed to various bacteria and viruses over our lifetime. Just like fighting a bully, the more your immune system stands up to infections, the stronger it gets. Rob the immune system of this form of “combat exercise” and you’ll grow up with an undeveloped and weak defense mechanism.
Now researchers have found a link between growing up “clean” and developing colon disease later in life. The moral of the story, let your kids roll around in the mud and don’t freak out if your house isn’t spic and span. A little dirt won’t kill them, it may actually heal them!