The use of faecal transplants to treat severe infections has rapidly become the treatment of choice, but as use increases and widens proper screening of donors, and good long term trials and monitoring are urgently needed in order to provide sensible advice to patients, say experts in The BMJ.
Gut microbes play a key role in our immune systems and health - and transplanting faecal matter from one person to another is increasingly being used to control severe life-threatening infections like recurrent Clostridium difficile that kill thousands of people annually.
The procedure involves introducing a liquidised stool (or frozen microbes) from a healthy donor to the bowel of a patient to re-colonise their gut with healthy bacteria, which are often destroyed after prolonged antibiotic treatment.
An analysis of the evidence found an 85% success rate with faecal transplants compared with only 20% success for standard antibiotic treatment. And a recent trial was stopped early because of the overwhelming superiority of faecal transplantation, with 90% success rate compared with 26% for powerful antibiotics.
So far, after over 7000 transplants, few adverse effects are being reported, and despite early fears, transplants even seem relatively safe in elderly patients or those with an impaired immune system, say Professor Tim Spector from King's College London and Professor Rob Knight from the University of California San Diego.
Over 500 US centres now offer faecal transplantation, most supplied from a single lab in Boston, and the use of faecal transplantation for C difficile infection has now been cautiously endorsed by the American Academy of Gastroenterology and European Society of Microbiology and Infectious Diseases.
While European and Australian regulators are stalling, the UK regulator (MRHA) has temporarily classed faecal transplants as a medicinal product (with exemptions from many of the usual regulatory barriers) and the procedure has been approved by NICE. But in contrast to the US, the UK now has only around seven centres that offer the treatment.
While "it is clearly better than further antibiotics for treating conditions like C difficile", the use of faecal transplantation is being increasingly tested in other common conditions, including obesity, diabetes, irritable bowel syndrome, colitis and many others. However, claims that faecal transplantation could be a cure-all for many diseases, "are probably too optimistic," say Spector and Knight.
As well as the obvious risks of infection (reduced by screening), there are longer term potential risks of transferring microbes to a new host, which could include transferring susceptibility to obesity and even mental illness, they write. "These possible risks suggest that faecal transplantation, although an exciting new tool, should be carefully monitored and refined to include most of the key beneficial microbes."
"We urgently need more expertise and centres, proper screening of donors, and good long term trials and monitoring procedures in order to provide sensible advice," they conclude. Otherwise, patients with many chronic complaints "may lose patience and take matters into their own hands (using DIY methods) with unpredictable consequences."