Being dirty may make you healthier.

A comparison between wild rats and their labratory cousins shows that the wild rats have much better immune systems. It is easier for them to fight disease, and their systems do not over react to allergies or on-dangerous pathogens. Dr. Parker hopes to achieve more definitave research on this, once he builds an artificial sewer to raise rats in.

I have known about this for years. Seriously, I eat wierd stuff, bathe about once a week, and wear dirty clothes over again. I havn't been sick for 4 years now. Not even a 24 hour cold. So there.