Dr. Scott Harris, a gastroenterologist and professor of medicine, Georgetown University Medical Center, Washington, said the trial was likely underpowered, and that by including patients with less severe disease, it may have been more difficult to see a treatment effect. Other trials have also shown that 6 weeks of therapy may not be enough for refractory patients.
"I’m very optimistic, I wouldn’t stop at this point," he said.
Session cochair Dr. John M. Inadomi, professor of medicine and head of gastroenterology, University of Washington School of Medicine, Seattle, agreed that the length of treatment as well as the study’s use of anonymous donors could have affected results. One of the big questions is whether the donor feces actually grafted and thus affected the recipient.
"If you use the wrong donor stool, if the stool didn’t graft, these kinds of things can obviously make a negative result, even if the concept is potentially fine," he said in an interview.
Last year, the Food and Drug Administration moved to require an investigational new drug permit to treat C. difficile with fecal microbiota, but changed course within weeks citing public pressure. While researchers are studying the potential to deliver feces via capsule, Dr. Moayyedi observed that some enthusiasts are offering Internet advice on how to mix your own FMT at home.
Dr. Moayyedi reported financial ties with AstraZeneca Pharmaceuticals, Forest Laboratories, and Shire Canada. Dr. Harris reported no conflicting interests. Dr. Inadomi reported financial relationships with Given Imaging, ChemImage, Cernostics, and Epigenomics.