They Might Sound Gross, But Intestinal Worms Can Actually Be Good Tor You

Intestinal worms have an incredibly bad reputation. The thought of them sneaking around inside our bodies and eating us from the inside is pretty unpleasant. But just 100 years ago, before toilets and running water were commonplace, everybody had regular exposure to intestinal worms. Thanks in part to modern plumbing, people in the industrialized world have now lost almost all of their worms, with the exception of occasional pinworms in some children.

http://www.iflscience.com