Host-Bacterial Mutualism in the Human Intestine -- Bäckhed et al. 307 (5717): 1915 -- Science:
New studies are revealing how the gut microbiota has coevolved with us and how it manipulates and complements our biology in ways that are mutually beneficial. We are also starting to understand how certain keystone members of the microbiota operate to maintain the stability and functional adaptability of this microbial organ.
A review of the state of knowledge on the evolution of the human gut ecosystem. Lots of diseases to cure there, and evolution is at the core of it all.