Fecal microbiota transplantation to fight infections and other intestinal diseases.

We have analyzed fecal bacterial and viral communities of a patient with recurrent infection (rCDI) who was cured by fecal microbiota transplantation (FMT). The "Zürich Patient" experienced immediate cure and has remained free of symptoms for now over 5 y. Donor-similar bacterial compositions after 4.5 y post-FMT demonstrated sustainable engraftment of donor microbiota predominated by and bacteria. Appearance of beneficial species and was detected while disease-related decreased. Stabilization of the microbiota took longer than expected from the rapidly improving clinical symptoms, suggesting the need for longer-lasting patient observation. The virome was mainly composed of bacteriophages but surprisingly also contained sequences related to a giant virus that normally infects green algae not known to inhabitate the human intestine. FMT is highly effective against rCDI and is presently broadening its application to other conditions including inflammatory bowel disease (IBD). Here, we discuss the prospects and challenges of FMT against rCDI and other indications including a focus on bacteriophages.