Fecal Transplants: Getting To The Bottom Of The Matter

Many Americans will be introducing more food than usual to their GI tracts on this Thanksgiving Day, and so I thought I’d provide you with a special gastroenterology-related post to complement the mood. If you have already eaten, I might suggest that you come back to this post on an empty stomach. I will be discussing the alternative medicine practice known as “fecal transplantation” and it is rather unsavory.

The idea of transferring stool from one person to another (for the treatment of various GI disorders) was first described in the 1950s. This month the TV show, Grey’s Anatomy, featured the practice in one of their plot lines – which rekindled interest in the therapy, and resulted in an explosion of search engine activity. I figured it was probably my duty, as a member of Science Based Medicine, to offer a rational analysis of the treatment in the hope that the Google gods will serve up my post to a few of the information-seekers out there. I hope to reach them before the snake oil salesmen, wrapped in their mantle of “gentle, natural cures,” convince them that they desperately need a good colon or liver cleanse, if not a fecal transplant.

Like most alternative therapies, fecal transplantation is based on a drop of truth and a gallon of pseudoscience. It is true that the gastrointestinal tract is teeming with hundreds of thousands of bacterial species and pseudo-species, and that without them we would die. It is also true that certain nasty bugs (like clostridium difficile) cause problems when they take up residence within the gut. Antibiotics do upset intestinal flora, much to the consternation of infectious disease specialists. Now, all that being said – the practice of repopulating the gut with another person’s stool requires some fairly grand assumptions about efficacy and safety that are not founded upon any clinical trial data whatsoever.

How It Works
My friend and pro-science advocate, Dr. Brian Fennerty, explained to me that the process of fecal transplantation (as described in the literature) requires a few steps. First, the undigested matter from the donor stool must be removed with some sort of straining device. Next the remaining fluid is spun in a centrifuge to reduce the material into a bacterial “pellet.” Finally the pellet may be introduced to the patient through a nasogastric tube, or reconstituted in liquid and inserted into the rectum in the form of an enema.

The Underlying Assumptions
In order to recommend fecal transplantation, one would have to make a number of assumptions. These giant leaps present little cause for hesitation among some alternative medicine practitioners:
• That gut derangements (such as inflammatory bowel disease) are caused by imbalances in intestinal flora
• That gut diseases could be improved or treated with introduction of donor stool to the GI tract
• That donor stool will provide the right sort of bacterial colonies to restore the correct “balance”
• That bacteria from donor stool will actually colonize the new gut, rather than exit with the next meal
• That a recolonization will endure long enough to affect the underlying disease being treated
• That donor stool will not introduce any unwanted pathogens
• That there are no negative side effects (sepsis, perforated colon, exacerbation of colitis, etc.) that outweigh the possible benefits.

The Dangers
The human GI tract is not just full of bacteria, but it can also be populated with viruses, fungi, protozoa and parasites. Fecal transplants can transmit HIV, prion disease, e. coli 0157:H7, worms, shigella and other dysentery-causing infectious agents. Current laboratory testing is unable to detect all possible pathogens, especially prions. It is therefore impossible to declare a stool sample “safe” with our current technology.

The Scientific Literature
To my knowledge, there have been no controlled trials to evaluate the outcomes of fecal transplants. There are several observational studies suggesting that patients with c. diff colitis and certain inflammatory bowel conditions improve after the introduction of donor feces. Of course, observational studies do not establish that the treatment is more efficacious than a tincture of time.

A summary of the literature (with references) may be found here. Ironically, the website that features these references claims that fecal transplants may be helpful in the treatment of everything from heartburn, to immune deficiencies, to autism.  Apparently, they didn’t analyze the literature they cite.

There is currently insufficient evidence to recommend fecal transplantation for any patient. There are clear risks, and no proven benefits.

The Last Word
After reading this post my husband asked me, “How much do they pay donors?”

Posted in: Surgical Procedures

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11 thoughts on “Fecal Transplants: Getting To The Bottom Of The Matter

  1. Airbag says:

    It’s interesting to see what the results are in controlled studies for c diff colitis. A controlled study has apparently been started in Netherlands:

    The initial results seem quite promising:

  2. Mark Crislip says:

    when it comes to C. diff there is good biologic plausibility the stool transplant should be efficacious. I have yet to try it, but several colleagues in the city have with good result. I think I would be puking too much to be of use.

    For literature I refer to
    which is of interest.

    They usually give spouse stool, and screen the patient like an organ transplant, so risk is rather low. I went to a lecture once that suggested the stool of children matches better and there may be genetic component to your gi flora.

    With refractory C. diff, esp the new hypervirulent strains that respond poorly if at all to antibiotics, it may be worth a try rather than colectomy.

    I think the conclusion is a wee bit overstated; given the understanding of C. diff I think that it is highly probable it would be an effective if disgusting treatment. It may not be evidence based yet, but it is somewhat science based.

  3. Peter Lipson says:

    IVIG has been studied in severe c diff as well.

    But fecal transplants are not too implausible, and have been studied a bit. So has the idea of colonizing people with non-toxogenic c diff…

  4. hatch_xanadu says:

    Wait . . . a nasogastric tube?

    So patients are subjected to a ridiculously uncomfortable procedure in order to get somebody else’s poop into their stomachs?


  5. storkdok says:

    My husband had to ask why I was laughing uncontrollably. When I started to read this to him, he put his fingers in his ears and said, “Ewww, stop, stop, that is so gross!” Typical anesthesiologist!

    My first thought, as your husband’s, was, how much do they pay the donor?

    My second thought, does the NGT make it a little more “palatable”?

    My ickometer is high, in the gagging range.

  6. Dr. Val’s husband wins the internet!

    Also, EWWWWW!

    Also also, I shall exercise all due vigilance to ensure no parent of any children with autism in my sphere of acquaintance are tempted by this treatment. (Because kids with autism have enough sh*t to put up with already!)

  7. Fifi says:

    I’m with Dr Crislip here regarding poopooing this idea off the top. While I think the ick factor makes the idea unattractive to most of us and there is a whiff of SCAM simply because SCAM can be somewhat poo obsessed and talks about the body’s ecology (usually erroneously), that doesn’t mean this might not be an effective treatment for what can be a very debilitating condition for quite a lot of people.

    There are increasingly indications that E. coli combined with genetic factors are at play in Crohn’s.

  8. Zetetic says:

    Seems I recall there used to be some sort of colon bacteria cocktail given to patients in the past – Is this still a practice modality?

  9. hatch_xanadu says:

    I imagine the NG tube does, in fact, make the practice seem more “medical” and, therefore, more legitimate.

  10. skeptyk says:

    Dr. Val, I’m your number two fan!

    Perhaps the NG tube makes it safer? because all the other poo fauna – which could take a detour into the body via mucosa in a PO dose – will be dumped directly into the hostile cauldron of stomach juice? Just a guess.

    I read this hot on the heels of playing post-holiday catch-up on my blog-browsing, where I just read about urine enemas (for acne), urine and castor oil compresses (for thyroid cancer) and urine quaffing (for damn near everything). Good news from the waycrazy College of Natural Nutrition site is that any pee will do for those enemas: “Old or fresh whatever you’ve got”

    Thanks to Dr*T and Dr Crippen for nourishing my inner 4th-grader:

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