Faecal transplantation, also known as faecal bacteriotherapy, is a procedure that involves the removal of stool from a healthy donor and the infusion of that stool – and all the healthy bacteria it contains – into the microbial environment of the sick patient.
Specifically, the review found that for recurrent infections caused by the bacteria Clostridium difficile (C. difficile), the intervention is successful 85 percent of the time. Faecal transplants also helped 55 percent of patients for whom standard drug treatments didn't work.
C. difficile can be picked up in hospitals and doctors' offices, and in 2011 the bacteria was to blame for 500,000 infections and 29,000 deaths, according to the U.S. Centres for Disease Control and Prevention.
"C. difficile is an increasingly common intestinal infection, usually, but not always, triggered by prior antibiotic use, and characterised by bad diarrhoea," explained study lead author Dr. Dimitri Drekonja. He is a staff physician in the department of infectious diseases with the Minneapolis VA Health Care System. In general, the infection "is relatively easily treated (and) 90 percent of people do improve," he added.
"But nowadays it seems to come back at a relatively high rate," Drekonja said, noting up to a 30 percent recurrence rate. "And 40 percent of those get it again after that," he said.
The problem is that "C. difficile can exist in the environment for a long time," he said. And, because standard antibiotic treatment kills both bad and good bugs, such treatments can contribute to recurrent infections.
Interest has been growing
"So, over the last 15 years, and in particular in the last three to five years, interest in faecal transplant has been growing," said Drekonja, who's also an assistant professor of medicine at the University of Minnesota.
"Right now it's an investigational and invasive procedure, and most of the data we have has come from case reports that may or may not be fully representative. But our review, which includes two recent high-quality controlled studies, seems to confirm the largely positive results we've been hearing about."
The study, which was funded by the U.S. Department of Veterans Affairs, is published in the Annals of Internal Medicine.
The review looked at the findings of two randomized, controlled trials – the gold standard of scientific research – as well as 33 uncontrolled case reports involving more than 500 C. difficile faecal transplant patients.
The conclusion: faecal transplantation appeared to be effective while prompting few short-term side effects.
But the investigators cautioned that the available data is "low-strength". They also said there isn't enough evidence for drafting guidelines regarding how to determine ideal donor candidates, how to identify ideal faecal-preparation methods, or how best to deliver the sourced stool to patients.
Not yet FDA approved
"I think this will be a hot area going forward," said Drekonja. "But the evidence we have so far does not meet the criteria of FDAguidance, which means that if this was a standard pill under development and brought to the FDA for approval with the information we now have, it would not be licensed."
But, he added that his team and others are continuing to study faecal transplants.
Jeffrey Cirillo is a professor in the department of microbial and molecular pathogenesis with the Centre for Airborne Pathogens Research and Tuberculosis Imaging at Texas A&M Health Science Centre College of Medicine in Bryan, Texas. He suggested that the new analysis is an "exciting" step in the right direction.
"This is a very nice review of the available literature, and their conclusions are supported by the studies that they review," he said. "This is the first time that this type of treatment strategy has been reviewed in such a comprehensive manner."
Faecal transplants do appear to work "fairly well," he added.
Image: Small and large intestine from Shutterstock