This is a short summary and I suppose this is as good place to put it instead of starting a new post (more of "nice to know" research):
MICROBIOLOGY:
Detoxifying Enzyme Helps Animals Stomach Bacteria
Evelyn Strauss
Last week, microbiologists reported that when bacteria colonize vertebrate intestines, the tissue produces an enzyme that appears to defuse a dangerous toxin the microbes wield, helping to explain how we can live in peaceful coexistence with the scads of potentially noxious bacteria in our guts.
(from http://www.sciencemag.org/cgi/content/summary/318/5858/1853a)