Scientists discover hundreds of strains of bacteria in intestines.

Byline: Glennda Chui

SAN JOSE, Calif. _ One hundred trillion bacteria live in your gut _ 10 microbes for every human cell in your body.

In the first comprehensive survey of this realm, Palo Alto, Calif., scientists found 395 strains of bacteria living in the intestines of healthy people. Most were previously unknown to science.

They discovered that each person's collection of bugs was unique and varied from place to place within the gut, which is more than 30 feet long when uncoiled.

Some bacteria cling to the intestinal wall, while others hitch rides on bits of undigested food, forming colonies that researchers jokingly call "Whovilles."

Sounds gross, but it's actually a good thing,…