Bollrath,J, Powrie,F,Science 341:463-464, 2013
The human intestine harbours up to 1011 bacteria per gram of intestinal content, comprising over 500 different species (1) that have coevolved with their hosts in a mutually benefi cial relationship.
These bacterial communities promote human health through effects on nutrition and immune system development and function, changing in distinct ways over time and in different disease states.
