Last week, I wrote about scientists who developed a stool substitute and used it to cure gut infections in two women. This sham poo contained 33 gut bacteria, which were meant to displace the harmful ones that were causing diarrhoea in the patients.
For decades, doctors have been doing the same thing using actual faeces. This unorthodox technique, known as a faecal transplant, has been used to treat over 500 people with recurring infections of the diarrhoea-causing bacterium Clostridium difficile.
The concept is inherently revolting, and many mistake it for pseudoscience. But faecal transplants work. Over 90 percent of patients make a full recovery, far greater than the proportion who responds to conventional antibiotics. (In fact, it may be antibiotics that cause recurring C.difficile infections in the first place, by annihilating the beneficial gut bacteria that normally keep such infections at bay.)
Some might argue that all of this amounts of anecdotal evidence. Faecal transplants have never been tested in a randomised clinical trial – the gold standard of medicine. But that objection no longer applies. The first results from a faecal transplant trial have been published in the New England Journal of Medicine, and they are a resounding vindication for the technique.
The infusions of faeces cured 94 percent of patients who received it (15 out of 16), all of whom had already suffered at least one relapse of C.difficile. By comparison, the standard antibiotic—vancomycin—only cured 27 percent of patients (7 out of 26). The difference was so great that the Dutch team behind the study had to stop the trial early. Everyone eventually received the faecal transplants.
The technique had no negative side effects except for the rare bout of constipation, and diarrhoea for a few hours after the infusions. That’s nothing compared to the gastrointestinal agony of a bout with C.dfficile.
I’ve written about the trial for Nature News, so head over there for the details. For now, I’ll highlight a couple of points from the trial.
First, most faecal transplants are done through an enema. But this team used a tube threaded through the nose and down into the small intestine, thus horrifically redefining the term “brown-nosing”. Apparently, this is quicker and easier in cases when the colon is inflamed, as it frequently is in people with C.difficile.
Second, faecal transplants are thought to be off-putting, and the team says that young patients tend to be more reluctant about it. But older ones, who have suffered through their infections for a long time, are eager to try it, given its reputation for success. Els van Nood, who ran the trial, told me that contrary to expectations, patients were sorely disappointed if they weren’t randomised into the faecal transplant group.
Third, van Nood is still keen on somehow standardising the procedure, which will make it easier to gain regulatory approval for it. Often, people are allowed to choose their own donor, but that can cost them precious time as the volunteer has to go through rigorous screenings to ensure that they don’t have any health problems. One alternative, as in this new trial, is to use faeces from a fixed pool of donors, whose stools are frozen until they are needed (and another trial is comparing the effectiveness of fresh vs frozen stool).
The other option is, as in the study I wrote about last week, to create a stool substitute. “It’s very nice that the two studies came out together,” says van Nood. “We’d like to see progress to a more standardised product – a medicine that you can give if someone that consists of the right bowel flora.”