Humans, like other animals, have a large and varied population of beneficial bacteria that live in the intestines. The bacteria break up large molecules that the host cannot digest. The host in turn absorbs many of the resulting small molecules for energy and nutrients.

"The number of bacteria in our gut far exceeds the total number of cells in our bodies," said Dr. Yanagisawa.

"It's truly a mutually beneficial relationship. We provide the bacteria with food, and in return they supply energy and nutrients," he explained.

Most amazing in this account, is the degree of symbiosis that exists between highly complex organisms such as humans and mice on one hand, and bacteria on the other hand. Life is interconnceted.

One thing is for sure: you never walk alone