Poo The Elixir Of Life: don’t pooh-pooh the facts on faecal microbial transplant therapy

Why do we find the concept of transferring faeces, stool, poo, s**t, from one person to another bizarre? After all, many of us donate blood and some of us our organs, so why not poo too?

FMT History

Poop cure-all is steeped in history. In India, dating back 3000 years, cow dung and urine was used to treat colon disease. Fresh and fermented human poo has been used in Chinese medicine since the fourth-century. A special poo concoction called ‘yellow soup’ has been used to treat food poisoning and diarrhoea. If you had dysentery the Bedouins would have had you drinking fresh warm camel dung. This all sounds a little extreme we must admit.

It wasn’t until the late 1950s that two American doctors used faecal microbial transplant (FMT) as a tool to treat colon conditions. Dr Ben Eiseman, a surgeon at the V.A. Hospital in Denver, used poo from pregnant women, thought to be young and healthy, transferring it into very poorly patients whose gut microbes had become depleted after taking antibiotics. In 1957 an eager microbiologist called Stanley Falkow was sacked from his hospital job after being accused of feeding sick patients s**t! Falkow realised patients who took preemptive antibiotics before their operations didn’t get a nasty Staphylococcus infection, which is good, but very often they soon became ill with diarrhoea, indigestion and other uncomfortable bowel conditions. Falkow thought their depleted gut microbes cover be recovered by treating them with poo from healthy people. It worked! After a couple of days, Falkow was back at work again and went on to become one of the most influential microbiologists of the last 50 years!     

FMT in Practice

Over the past ten years technical developments have enabled scientists to understand more about the human microbiome. During this time FMT has been used to treat a hospital-acquired bacterium called Clostridium difficile or C diff. This bug can live harmlessly inside us. But in patients who received antibiotics, C diff can not only survive but dominate the gut microbiome. C diff releases potent toxins causing severe, recurring and potentially fatal bouts of diarrhoea in the individual. When a patient receives an infusion of poo, many clinical trials have shown that levels of C diff return to a baseline state and the patient recovers. There is even a flourishing community of DIY enthusiasts who have tried DIY FMT, but we don’t recommend you try this at home!

Faecal Microbiota Transplants (FMT) for treatment of serious infection. Created by the Quadram Institute, UK.

Current Studies

FMT is being used to treat patients suffering from Inflammatory Bowel Disease (IBD), particularly Ulcerative Colitis (UC), diabetes, obesity, anorexia and more. Over two hundred trials are listed on clinicaltrials.gov.

Many papers highlight that FMT poo microbes are responsible for influencing positive inflammatory pathways in these patients. The transplanted stool results in a balanced homeostatic shift in the gut microbiota, restoring many metabolic pathways. Key gut bacteria, such as the short-chain fatty acid (SCFA)-producing families are enriched, including Ruminococcaceae and Lachnospiraceae and the genus Roseburia.

These amazing bacteria seem to cause an increased production of anti‐microbial peptides, specific defensins, secretory immunoglobulin A and mucin. In particular, Bacteroides fragilis‐derived polysaccharide A, which is a large sugar molecule found on the surface of the bug, induces changes in T cells which play a valuable role in strengthening the immune system.

In UC, Clostridia have been identified as a key leading player in the maintenance of gut homeostasis. Excitingly, Phase 1 clinical studies towards exploring the efficacy of human commensal Clostridia strains for the treatment of IBD are currently in progress (Vedanta Biosciences).

How it all works isn’t exactly clear. We don’t know whether the bugs alone, the molecules produced by the bugs, or a combination of both is best. FMT works for many people, which is great news and increasing research means we will literally get to the bottom of it!

Further Reading


Picture: Fernando Trabanco Fotografía / Getty