Dr. Alexander Khoruts is a gastroenterologist at the University of Minnesota. In 2008 he was presented with a tough case of Clostridium difficile and chronic diarrhea, that nothing seemed to help. His patient was wasting away and he was running out of ideas.
Finally he decided to deliver some of her husband's bacteria into her colon. To his surprise and relief, her crippling diarrhea disappeared within 24 hours. So did her Clostridium difficile infection. It has not returned.
Fecal transplantation is an ignoble sounding treatment. But it was a life saver. Her husband's imported bacteria had won out over the unhealthy flora in her intestines and brought health back to her.
"Scientists are regularly blown away by the complexity, power, and sheer number of microbes that live in our bodies. 'We have over 10 times more microbes than human cells in our bodies,' said George Weinstock of Washington University in St. Louis. But the microbiome, as it’s known, remains mostly a mystery. 'It’s as if we have these other organs, and yet these are parts of our bodies we know nothing about.'"
http://www.nytimes.com/2010/07/13/science/13micro.html?_r