1. The only approved use of “FMT” is for recurrent infection with Clostridium difficile, which causes severe diarrhea. The infection is usually acquired in a healthcare facility. A 2013 FDA “enforcement discretion” ruling allows doctors to provide FMT without filing an Investigational New Drug Application – but only to treat C. difference infection (CDI). It’s 90% effective! The procedure is in clinical trials for other indications, albeit in a context of widespread DIY variations on the theme.
2. The procedure could become a first-line treatment for CDI, not just a last resort when antibiotics have failed to control the terrible torrents of watery stool. And it is necessary. Results of a study published in the Annals of Internal Medicine found that cases of multiple, recurrent CDI – more than two episodes in a short period of time – are increasing at more than four times the rate of the overall infection. The numbers are frightening: up to half of the 500,000 people in the US who receive CDI annually get it again at least once, at a total cost of more than $5 billion a year. Drug-resistant strains are emerging and new drugs are hitting the market, but a fecal transplant could be the solution from the start. CDI, say many who have had it, is a lot worse than getting over the “ick factor” of getting a little foreign poop.
3. Some medical organizations and insurance companies (including Medicare) cover fecal transplants for CDI.
4. What happens during evacuation? From 25% to 54% of the solid portion – after removing the 75% that is water – consists of bacteria. The rest are undigested nutrients, electrolytes and mucus, with the color of bile pigments and the odor of bacterial compounds (phenols, indole, skatole, ammonia and hydrogen sulfide). But the composition of feces varies daily between individuals, which will complicate the standardization of transplants. It also presents an obstacle to using a microbiome profile as a form of identification. One bioethicist mentioned checking feces at airports to see if travelers came from immigration-banned countries. Would a Swede’s passport be accepted if his feces contained bacteria native to Somalia?
5. Fecal transplants may conjure mental images of turkeys, but the material is delivered via enema, colonoscope, nasogastric tube (a nasal hose) or capsule.
6. Technology is at least 1,700 years old. The first recorded use was in 4th century China, by a doctor, Ge Hong, to treat food poisoning and diarrhea. At various times and places, poop was delivered as “yellow soup” to humans and other animals (especially cattle) and German soldiers reportedly infused camel feces to treat bacterial diarrhea during World War I.
7. Reductionists who try to delve into the good things about a poop and then recreate it note that only part of a microbiome needs to be transferred, similar to a key organism in an ecosystem. SER-109 from Seres Therapeutics – a capsule that delivers “an ecology of enriched and purified bacterial spores from selected, healthy human donors” – is in Phase 3 clinical trials to treat CDI. More mysterious is SER-262 – “the first synthetically derived and engineered therapeutic microbiome.” It did well against placebo in a 24-week phase 1 randomized controlled trial.
8. Researchers are working hard to describe the ideal stool donor. Most references cite the Amsterdam protocol in this regard. And the American Gastroenterological Association maintains a National FMT Registry to monitor adverse events and donor details. Will we one day have poop centers similar to frozen yogurt shops, where a hopeful recipient can request a specific fecal microbiome? Or even mix flavors?
9. Altering the gut microbiome could treat autism, Parkinson’s disease, depression and anxiety, perhaps by affecting serotonin levels, thanks to the “gut-brain axis.” In an intriguing experiment, feces from people with severe depressive disorder had a different effect on “depression-like behaviors” when transplanted into germ-free mice, compared with the rodents’ more vigorous response to feces from happy humans.
10. Should people pay for poop like they do for sperm? Should we patent exceptionally curative gifts? Does anyone remember The Repository for Germinal Choice, an ill-fated California sperm bank for Nobel Prize winners?
11. Delivery. Once stool donations are standardized, how will they be prepared and sent? Dried up like sea monkeys? Fedex? UPS? Amazon Prime?
12. Should informed consent for a recipient include knowledge of the donor’s diet? Would a transplant from a person who ate pork be like implanting pig heart valves into an Orthodox Jew? Can a recipient request a vegan donor?
13. OpenBiome is a non-profit stool bank that ships frozen matter to hospitals. Founded by a relative of someone who fought futilely against CDI with seven rounds of vancomycin before a transplant helped, the company pays $40 for donations several times a week for two months. The feces must go through two rounds of screening, and the original owner must be between the ages of 18 and 50, have a BMI of less than 30, and live near Cambridge, MA, where donations are deposited. The homepage opens to an image of clean, white bottles – combating the ick factor is a big challenge for this emerging industry.
14. Fecal transplantation can have unexpected effects, especially because its standardization as a medical substance is a major challenge. The first observation was obesity, which is kind of obvious, but a man who had suffered from alopecia since he was 6 had a transplant to treat CDI and grew so much hair that he had to shave!
15. AdvancingBio treats private payers. The preparation costs US$115 and delivery depends on the route: “esophagogastroduodenoscopy” (in the hatch) costs US$307 and colonoscopy from US$341 to US$591. The “become a donor” page shows 10 smiling people, most of them millennials. Those wishing to sell their excrement must be between the ages of 18 and 65, have a BMI of less than 35, provide a medical history and have a blood test to detect infections, including cholera, E. colipest, transmitted by food Salmonella It is Shigella, as well as various eggs and larvae. Presumably the donation should score a healthy type 3 or 4 on the Bristol Stool Chart.
Stay tuned. Scatological jokes aside, fecal transplantation is a valid medical procedure that will likely continue to find new niches.
Ricki Lewis has a doctorate in genetics and is a genetic counselor, science writer, and author of Human Genetics: The Basics. Follow her on her website or @rickilewis.