For a patient who has been infected by the Clostridium difficile bacteria, or C. diff – inflammation of the colon is inevitable, with some ending fatally. The US Centres for Disease Control and Prevention (CDC) says C. diff kills up to 29,000 people a year. A cocktail of antibiotics to cure the infection will tend to wipe out both the good and bad bacteria in the intestines, leaving the environment barren, save for C. diff, which can sometimes be strain-resistant.

Stronger antibiotics to ward off C. diff may just do the trick. However, the bacteria often recurs. Fortunately, when the infection is not responding to standard therapies, the patient has the option of having a faecal microbiota transplant (FMT).

More than just waste

FMT, or a stool transplant is a procedure gaining in popularity to cure C. diff infections. Through an enema retention, a donor’s faeces are transplanted into the patient’s bowels to improve the balance of good and bad bacteria. A stool sample is screened, liquefied and delivered to the patient’s colon by nasal or rectal tube, much like a colonoscopy. FMT demonstrates a high success rate of 90%, without the patient relapsing.

The downside to FMT administered this way is that a patient must find a donor or resolve to a stool bank. Donors with healthy stool is only a miniscule population of 3% in the US. Samples also differ in preparation and quality checks from one stool bank to the other. The US Faecal Transplant Foundation also states that there is little regulation on the matter.

“Every donor is different. Every centre preparing faecal transplants is different,” said David Cook, head of research and development at Seres Therapeutics. “It doesn’t undergo the kind of rigorous checks for quality control that a modern pharmaceutical does.”

In addition, this method of delivering FMT introduces the risk and imposes the cost of a colonoscopy, which many still find to be invasive.

“It’s a very simple procedure,” asserted Catherine Duff, founder of the Faecal Transplant Foundation and seven-time C. diff survivor. “The major barriers to people doing it are finding the right donor and, I guess, what you call the ’ick’ factor,” she added.

Orally consuming faecal microbiota

Numerous studies have been done in the field of intestinal health, where several infections and diseases are intimately linked to changes in the composition of the gut microbiota. FMT is advancing, mainly due to the existing pool of patients that readily awaits. Half a million instances of C. diff infections are recorded every year in the US, with 85,000 – 110,000 patients likely to experience a relapse. Pharmaceutical companies are aware of this and plan on sidestepping the ‘ick’ factor by delivering FMT through pills.

James Mcllory, CEO of EnteroBiotix, a biotechnology company that is making headway with the pills said that this approach would be more scalable to patients. “FMT delivers many strains of bacteria from the donor sample, but only certain strains stay in the recipient,” he said. “Some donors seem to be better suited for some patients than others. This means that it may be possible to use the results of successful FMTs to inform the design of cultured cocktails of bacteria.”

Currently, the US Food and Drug Administration (FDA) still considers FMT as a last resort when all other therapies have failed, and holds the status of ‘investigational treatment’ despite its successes. It is with great hope that encapsulated FMTs could turn things around – with prices set to be competitive due to the many pharmaceutical players. Mcllory lamented, “the next phase with FMT will involve standardising the therapy and stratifying donors and patients.”

The potential also exists for FMT to treat other illnesses, from various inflammatory bowel diseases to maybe even obesity, diabetes and auto-immune diseases. Nearly 200 clinical trials of the treatment in various forms are under way. MIMS

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