THE lure of a miracle cure is strong, even if it involves someone else’s excrement. Faecal transplants are rising in popularity around the world, and being used to treat an increasingly wide range of conditions. But concern, too, is growing among doctors about the potential for side effects.
A survey of faecal transplant practitioners carried out by Â鶹´«Ă˝ reveals anecdotal reports of patients showing unexpected symptoms after the procedure.
Faecal transplants are thought to work by overhauling an unwell person’s gut microbes by introducing those of a healthy donor. Clinical trials have shown that this works for people with otherwise untreatable – banishing the potentially fatal bacterial infection .
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When it comes to other disorders, though, there is not enough evidence to say whether the procedure works. That hasn’t stopped clinics and online forums recommending the procedure for everything from irritable bowel syndrome and ulcerative colitis to depression, arthritis, Alzheimer’s and even autism.
Is it time to apply the brakes? The gut microbiome is powerful (see “Bugs on patrol“) and it is becoming clear that transplants can have unintended effects. “We’ve taken a blunderbuss approach – we’re taking an entire stool with its zoo of microorganisms and fungus and viruses without really knowing what we’re introducing,” says of the University of Sydney, Australia, who performs the procedure. Ted Steiner, a gastroenterologist at the University of British Colombia in Vancouver, says: “It’s a stupid, unnecessary risk.”
“It’s a blunderbuss approach. We’re inserting a stool without knowing what’s in its microbial zoo”
Earlier this year, a slim woman who had received a stool from her daughter was reported to have developed obesity. This news prompted Â鶹´«Ă˝ to ask practitioners around the world about their experiences. Of 135 people surveyed, 52 responded, with 15 reporting that their patients had exhibited unexpected symptoms afterwards.
These are anecdotal reports, so don’t provide hard evidence of specific ways in which faecal transplants may help or harm people. And the effects could be unrelated to the procedure. But the reports support calls for regulators to clamp down on the transplants, which are unregulated outside North America.
“One faecal transplant recipient gained about 15 pounds. We have no idea what to do about it,” says Arnab Ray, a gastroenterologist in New Orleans, Louisiana. “Part of me would like to perform another transplant with a skinny patient, but we can’t do that.” Others report changes to skin, appetite, mood, improvement in dementia and sexual function, constipation and cases of inflammatory bowel disease getting worse.
Much larger and more rigorous studies would be needed to find out how big a problem these unexpected effects actually are. “All you can tell from the survey is that unexpected outcomes do occur. We don’t know how frequent they are,” says , a gastroenterologist in Oakland, California, who pioneered the procedure.
But such reports are worrying. One concern is that the procedure could introduce bacteria that boosts a person’s risk of developing disease later in life. For example, recent research has shown that while .
Another worry is that donated stools could cause infection. representing US health institutions recommend that donors fill out the questionnaire given to blood donors, and that donated faeces are screened for bacteria and viruses. But even this may not be enough. of the body representing European gastroenterologists, , points to the chequered history of blood transfusions. These gave thousands of people hepatitis C and HIV in the 1970s and 80s. “No one can guarantee you that no dangerous viruses are in the gut microbiota,” he says.
In the US, the has issued guidance stating that faecal transplants should be treated in the same way as a new drug – any doctor wishing to do them must do so as part of a clinical trial, for which they must get permission. The exception is recurrent antibiotic-resistant C. difficile infections. .
Seven gastroenterologists contacted by Â鶹´«Ă˝ to comment on the survey results said that European regulators would do well to follow the FDA’s lead. But these organisations seem unwilling to act. The European Medicines Agency says faecal microbiota transplants fall outside its remit because they are not medicinal products. The UK says the organisation is in talks with the UK Human Tissue Authority to “get a better understanding of the use of FMT in the UK”.
Part of the problem is that faecal transplants are hard to define, says Simon Goldenberg, a gastroenterologist in London. “It’s not a drug, it’s not a device – it’s in no man’s land.” This lack of oversight means that in the UK anyone can offer FMT for any disorder.
The UK National Institute for Health and Care Excellence has on performing FMT for C. difficile, but they aren’t very useful, says Goldenberg. “No one in the UK is taking responsibility.”
This is worrying because as it stands, performing faecal transplants for disorders other than C. difficile is bad medicine, says Steiner. “It’s charlatanism.”
Leader: “Unregulated faecal transplants could squander gut-bug promise“
Stool swaps – A potted history
4TH CENTURY is recommended for diarrhoea in China.
1958 An account of is published.
2011 Reports that faecal microbiota transplants might help with Parkinson’s and arthritis.
JANUARY 2013 First published clinical trial of faecal transplants for treating Clostridium difficile infection – 13 of the 16 people cured.
MAY 2013 The US Food and Drug Administration raises concerns over FMT and declares it must be treated as an investigational drug.
JULY 2013 After an outcry, the to allow doctors to use FMT to treat recurrent C. difficile infections.
FEBRUARY 2015 First published report of an unexpected side effect of FMT – a previously slim woman become obese after the treatment.
This article appeared in print under the headline “Concerns mount over gut-bug swaps”
Article amended on 1 January 1970
Since this article was first published, we have clarified when blood transfusions caused many hepatitis C and HIV infections.
