Fecal transplants cure most cases of persistent C. difficile infection, a study shows.

An increasing number of people have turned to this unorthodox treatment for relief from the debilitating condition. But this report marks the first time a randomized controlled trial — the highest form of scientific proof — has shown that the treatment is effective.

“It will lead us to the tipping point where … people may be more aware of the value of the normal bowel flora,” said Dr. Tom Louie, an infection prevention and control expert in Calgary who has performed more than 100 fecal transplants.

“This is verification that good bugs help.”

Louie was not involved in this study, which was published Wednesday in the New England Journal of Medicine. It was done by researchers from the Netherlands.

The team used a tube snaked from a nostril down into the duodenum — the top of the small intestine — to deliver the fecal transplant to a patient’s intestinal tract.

The donor feces, from people who were screened for a variety of infectious diseases, were mixed with saline, stirred and then allowed to sit. Later the fluid was separated from the solids and only the fluid was used.

The study was stopped early when it was clear fecal transplants were far superior to alternatives: the antibiotic vancomycin, which is the standard treatment for C. difficile diarrhea; or a treatment called bowel lavage — a cleansing out of the bowel, like the preparation for a colonoscopy — followed by vancomycin.

Of 16 patients who received a fecal transplant, 13 were cured of their C. difficile after a single treatment. Two of the remaining three were cured after a second transplant from a different fecal donor, for an overall cure rate of 94 per cent.

Only four of 13 patients (31 per cent) who received vancomycin were cured; three of 13 (23 per cent) who had the bowel lavage followed by vancomycin were cured.

After the trial was completed, the people who had not been cured by the antibiotic were offered the option of a fecal transplant. Eighteen additional patients underwent the procedure and 11 were cured on the first try. An additional four were cured after a second transplant.