Estimating the risks of faecal transplants.

Recurrent Clostridium difficile infection (RCDI) is a severe and often fatal condition, killing an estimated 14,000 Americans per year. Treatment with faecal microbial transplantation (FMT) has been shown to be vastly superior to traditional antibiotic treatments, with success rates of around 90%. In studies performed so far, the stool (or its cryopreserved microbial content) of a healthy donor are introduced into the colon of the patient via a nasogastric/nasoenteric tube or the rectum via enema or during endoscopy (upper or lower), and more recently via cryopreserving donor microbes in acidresistant oral capsules. The speed at which this unorthodox therapy has been adopted (particularly in the USA) has surprised many people and governing bodies. Details on the risks of the procedure have been difficult to ascertain and Baxter and Colville in this issue of the Journal have performed an upto-date review of the evidence of safety of the procedure. They assessed 109 publications involving 1555 patients, the vast majority for RCDI. Their major conclusion was that the quality of the reported data is poor and that determining precise estimates of risk is problematic. Nevertheless certain conclusions may be drawn ethe first being that the overall rate of severe complications is low. They identified only three patients whose death may have been due to FMT, two of whom had experienced a procedure-associated complication and had been seriously ill before treatment. Although this treatment originated in fourth-century China, the first western use was in the 1950s and the first randomized controlled trial (RCT) in 2013. Already more than 500 US centres offer FMT, most supplied by frozen donations from the not-for-profit stool bank organization in Boston known as OpenBiome. FMT for RCDI has now been cautiously endorsed by the American Academy of Gastroenterology and by the European Society of Microbiology and Infectious Diseases. In the UK the National Institute for Health and Care Excellence approved FMT for RCDI last year, and the Medicines and Health Products Regulatory Agency temporarily classed FMT as a medicinal product for this indication only (with numerous exemptions). The US Food and Drug Administration, under pressure from patients and clinicians, has granted FMT a temporary exemption as an investigational drug (IND) for RCDI (nevertheless it encourages IND application). The caution is understandable because, although research efforts are underway, no good long-term data or registries yet exist.