As the Worm Turns: For 200,000 years, we humans have hosted parasitic hookworms and whipworms in our intestines.

As the Worm Turns: For 200,000 years, we humans have hosted parasitic hookworms and whipworms in our intestines. Until recently, that is: when antibiotics and better sanitation effectively “dewormed” much of the developed world. Coinciding neatly, was a perplexing rise in autoimmune diseases of the gut, like inflammatory bowel disease (IBD) and Crohn’s disease. Scientist Joel Weinstock wondered if there was a connection?

Whip it!: He began by treating mice with IBD. Animals fed enteric worms recovered from the disease. To test this therapy in humans, he chose Trichuris suis, a whipworm that typically infects pigs but causes no illness if swallowed by pig farmers. A patient with Crohn’s disease volunteered to swallow 2,500 tiny eggs (in a sports drink!) and his disease symptoms improved. Now, clinical trials are underway with many more patients, and the egg harvesting method has been approved by the FDA and European Medicines Agency. Other immune related diseases are also being tested: multiple sclerosis, autism, ulcerative colitis, psoriasis, and type 1 diabetes.

Old Friends Hypothesis: The idea behind the treatment is that our immune system can only become fully effective if stimulated by exposure to microorganisms and parasites that have low levels of pathogenicity, and which have coexisted universally with human beings throughout our evolutionary history. Autoimmune disease is caused by excessively high TH1 response, which is kept in check by an opposing TH2 response set off by infections. Of course, vaccines and public hygiene have greatly reduced disease and improved the quality of life in the past 100 years. The idea is to reintroduce some organisms into people in a controlled way, to improve human health without causing infectious disease.

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Image:  Trichuris whipworms, via


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57 Responses to As the Worm Turns: For 200,000 years, we humans have hosted parasitic hookworms and whipworms in our intestines.

  1. Rajini Rao says:

    The cellular basis for the cross protection is complicated and still being worked on, so I only touched on it briefly. In addition to the Treg cells I mentioned, infections also change the probiotic profiles in our guts, again modulating our immune response.

  2. There was an episode of This American Life on this exact topic a few years ago. I’ll see if I can find the link.

  3. Shirley Will says:

    Holy moley! That’s pretty awesome. IBS can be a problem for people with fibromyalgia as well, this is a great solution.

  4. Rajini Rao says:

    Thanks, Todd Henderson . There was a new perspective in this week’s issue of Nature magazine, unfortunately behind a paywall.

    I think it is pretty awesome too, Shirley Runyon . The trick seems to be a mild, ongoing infection that keeps the immune system in tune.

  5. … it was RadioLab that did the episode about a guy who tried this on himself. It’s an amazing, somewhat disgusting, story. Well worth a listen!

    This link is for an update page that references their original podcast but also includes more recent (2010) info about the guy.

  6. My eye was immediately drawn to psoriasis, this is a hereditary condition some of my family have, but I wonder if reintroducing worms or other parasites could help?

  7. Rajini Rao says:

    Self dosing not advised O_o!

    Although, I can’t resist retelling the story of Aussie scientist Barry Marshall who eventually proved that stomach ulcers was caused by bacterial infection..he downed a culture of Helicobacter pylori and made himself sick. He also won the Nobel prize for his efforts 😉

  8. Rajini Rao says:

    I’ll look into the obesity connection, if any, Feisal Kamil . Goodnight, and thanks for the fantastically hot #sciencesunday post! ❤

  9. Rajini Rao says:

    A google search on psoriasis and helminth therapy does bring up some sources worth following, Michelle Cameron . I’ll check in PubMed too.

  10. Rajini Rao that would be fantastic, unfortunately I don’t know enough about medicine to identify real remedies vs hoax remedies.

  11. Rajini Rao says:

    Wisely said, Michelle Cameron . There are so many hoaxes out there. Even this raised my eyebrows to begin with, until I read more of the primary literature. The pioneer of this treatment admitted that “The scientific and medical community initially received the hypothesis with a mixture of fascination and vocal scepticism”, and went on to say that they are more neutral now, as more data comes in. At least, the work is funded by reputable sources like the NIH, which is always reassuring.

  12. Mark Herndon says:

    Very true this is a big issue that I am sure many of us suffer from. Most don’t realize a large percentage of the population has pin worms. Its so very easy to get and it spreads about as easily too. I have a cat and I get her dewormed appx twice a year at her vet visits. She is also a full time indoor cat so that helps. My issue is that my job requires the use of hotel rooms several times per week. I have found over the counter medications like PinX however I worry about how often I can use the stuff.

  13. Rajini Rao says:

    I didn’t know that, Mark Herndon .

    What are the symptoms for humans?

  14. Interesting to think of yourself as a garden of sorts, for companion organisms.

  15. Mark Herndon says:

    WebMD has a great description of pin worms. It basically just a lot of intense itching.

  16. Brad Esau says:

    They say there’s a reason infants instinctively eat dirt.

  17. E.E. Giorgi says:

    this is fascinating; I’ve also read a bunch of papers that associated the decrease in microbiota flora in the skin with the rise of allergies. Makes you wonder, eh?

  18. Great post, Rajini Rao (as usual!). I’m fascinated by these developments, as they pile up. On the positive side for balanced immune system function: babies raised with (outdoor) cats and dogs; early exposure to soil streptomyces; et al. Topping the pile, fecal transplants. Maybe fecal transplants from farmers will become the next late-night infomercial craze?

  19. I have Crohn’s disease, and I can tell you that I will eat raw sewage during a flair up if it could take my pain away for just a day. Currently I’m enjoying a long remission brought on by high powered immunosupressents. How long it will last nobody knows… worms I would do any day if they made me better. Thanks for this!

  20. A fascinating discovery. Thanks for sharing that, Rajini Rao – your anecdote about self-administering scientists pushing science boundaries reminded me of this wonderful and shocking lecture given by Giles Brindley about Erectile Dysfunction:,

  21. I’ve been thinking a lot about this subject and one thought came when preparing dinner.  Stirring with a wooden spoon, then tasting from it, I realized that a wooden spoon can be a vector for self-innoculation of ‘healthy’ gut bacteria and also sharing those with your ‘family’.  Lots of people use plastic cooking utensils (dishwasher friendly I guess) but some of my wooden cooking tools are 35+ years old, and must be home to quite the colonies.  And I never get sick.

  22. Makes total sense. I was raised up in the garden of my grand dad, horticulturist. I ate radish straight from the ground, drunk well water in the garden extensions, play with cats. I was very rarely sick. My 2 brothers in contrary were brought up in a flat and they were often sick.

    But this has to do also with food. No point of talking about these vegan, detox or holistic medicine bs. Normal natural food, balanced with meat, salads, cheese etc… is the best for good health. If you kill the pathogen bacteria, you kill the good one as well, plus you don’t train your body.

  23. Roger Keulen says:

    Humans or other animals, never get born allone. And if you die, your not the only one who is dieing.

    Olivier Malinur And don’t forget these dirty animals ! Thay also are very good for childern under 2 years old. They don’t get sick they get stronger from them ! Just go to a pet zoo with your baby.

  24. Roger Keulen animals indeed, once when I was kissing my dog and laughing, saying “Poisonous dog germs” my boyfriend looked at me and said. “Well if they were poisonous you’d be dead, so I guess it’s ok”.  Sure is.

  25. Roger Keulen says:

    Why is what Olivier says holistic bs ?

    You body kill’s bacteria, but how does you body know how the bad bacteria looks like. Doesn’t have to learn this ?

  26. Rajini Rao says:

    Why are the seminars that I attend not accompanied by practical demonstrations, Mike McLoughlin ? 😉

  27. Roger Keulen says:

    I also think our body is a old design. So if you want to be healty eat things that grow on earth 25.000 years ago. So more beans and root’s and no bread (granes). Most food we made our selfs the last 3000 years, but that doesn’t mean our body is used to it.

  28. Rajini Rao says:

    There are a lot of feel good ideas out there, ranging from commonsense to eyebrow raising. It’s hard to tell what has biological basis, what has psychological effect, and what is bs! 🙂 Hopefully we make our decisions based on reliable information.

    David Archer , I still recall trying (and failing!) to school my face the first time I heard about fecal transplants 🙂

  29. Roger Keulen says:

    Roelf Renkema Ohh, sorry. (Maybe i didn’t read it well, englsh is not my primairy language)

  30. Roger Keulen says:

    It would also be great to have threaded comments on G+. It’s very difficult for me to read the conversation correct.

    #google   #googleplus   #googleplustips  

  31. Rajini Rao says:

    I agree on the threaded comments, Roger Keulen . We’ve been asking for them for a while, and Google is yet to deliver.

    That’s a great story about your son, Peter Lindelauf . I can tell that he has your sense of humor.

  32. Rajini Rao am surprised that fecal transplants were a new idea.  First heard of this back in my late teens (30+ yrs ago) in the UK.  There are also lots of ‘soil based organism’ yogurt cultures, my mom got some from an Amish farm around the same time period and the farmer was pretty clear about the health benefits.  Kept that culture going for years.  Perhaps we have forgotten more than we know.

  33. Rajini Rao says:

    Wow, no..I did not know that fecal transplants were used that far back. Perhaps they were “rediscovered” in the US (!) and that’s why I heard of them more recently.

  34. perhaps part of the problem is that treatments like these don’t make oodles of money as they can’t be patented since each person needs a unique blend of flora.  As we know from orphan diseases and drug shortages on inexpensive, short-term use medications, the pharma companies don’t give a damn.

  35. Rajini Rao says:

    The motivation for pharma is profit and they are responsible to their shareholders, like any other business. So in a sense, they are doing what they set out to do, and we shouldn’t hold them up to some nobler calling. As Chad Haney often says, this is the danger of expecting industry to do the research or find the therapy…we both agree that academics is better suited for this, since there research is not directly tied to monetary gain. But funds for research is dwindling…

  36. Roger Keulen says:

    Roelf Renkema And don’t forget the air condition that almost kill’s and cleans everything out of the air.

  37. Rajini Rao says:

    Unfortunately, Europe has as high rate of incidence of IBD as US 😉

    “As many as 1.4 million persons in the United States and 2.2 million persons in Europe suffer from these diseases.”

  38. Roger Keulen Air conditioners tend to barrage people with pathogens and toxins, as they keep air recycling within a given building, concentrating the industrial byproducts of modern building materials; and if not properly maintained, they provide breeding grounds for all sorts of nasty things. I don’t think it’s a problem of them being overly clean.

  39. Roger Keulen says:

    Rajini Rao Yes, but there more people living in Europe than US. Europe = 739,165,030, Us = 314,745,000.

  40. Roger Keulen says:

    So: 2.2 / 740 : 1.4 / 315 = 0.0029 : 0.0044

    So it’s a difference of more than 65%.

  41. Roger Keulen says:

    David Archer Yes, therefor we have ‘Dauerlüften” in our buildings. It’s in our building codes. You don’t need a air condition for removing fumes from building materials. The ‘Dauerlüften” doesn’t makes the air clean, it only makes it ‘fresh’. And that’s what you really need in air tight building that we have now.

  42. V. Devaney says:

    I believe the follow up studies on Tricuris didn’t pan out, but they are still exploring these theories.

  43. Rajini Rao says:

    Here are PubMed search results for Trichuris suis therapy:

    Worth a good browse for anyone interested. My take home is that it is working for IBD but still being investigated for other diseases. 2012 review from Kinet (well respected immunologist) quotes: “Efficacy has been demonstrated in patients with inflammatory bowel diseases and in 1 case of pecan allergy. Altogether, this information supports further investigation of T suis ova in patients with immune-mediated diseases, particularly in areas in which there is currently no therapy, such as food allergy.”

  44. Many of my colleagues that hail from less squeaky-clean countries have developed allergies several years after relocating to the well-Purelled Pacific NW. I wonder if it’s for similar reasons.

  45. Rajini Rao says:

    Kevin Marshall , indeed that is considered as supporting evidence for the “Hygiene hypothesis”. There are studies comparing rates of autoimmune dysfunction in pockets within the US too (such as native American reserves), on ethnic groups who have immigrated to the US (particularly the next generation) and within geographic regions of continents that range from developed to less developed. Although, the answer is not going to be quite that simple (nothing ever is!), it may play a significant part.

  46. Rajini Rao says:

    I’ll take the lazy weekend and a glass of wine, thank you Roelf Renkema 😉

  47. mahek abbas says:

    are there any types of diabetes..??plz tell me know if there are…

  48. Roger Keulen says:

    mahek abbas Diabetes mellitus

    1 – autoimmune destruction of insulin-producing beta cells of the pancreas.

    2 – insulin resistance and relative insulin deficiency.

  49. J Stasko says:

    I remember several years ago they were working on this for asthma but the reintroduction didn’t work.  As far as I know, this was recently noticed in 2005,

    It is interesting to hear that there is some success with other diseases.  It may not work with fully-developed type I diabetes, because once the beta cells are gone, they’re gone.

  50. Rajini Rao says:

    Mark Bruce , I’ve not read these papers since I just pulled them up from PubMed. It seems that helminth therapy is being investigated for rheumatoid arthritis, at least in mouse models.

  51. Rajini Rao says:

    We don’t want to go back to painful hookworm infections and disabling diseases that cripple and kill, Roelf Renkema . My point is the last sentence of this post, which is a quote from Dr. Joel Weinstock: “Of course, vaccines and public hygiene have greatly reduced disease and improved the quality of life in the past 100 years. The idea is to reintroduce some organisms into people in a controlled way, to improve human health without causing infectious disease.”

  52. Rajini Rao says:

    I agree, Roelf Renkema .

  53. Rajini Rao says:

    “Holism” backed by reputable science, not feel-good gurus Drew Sowersby 🙂 Isn’t that what we scientists would like to see? No wild claims of instant cures or anecdote based opinions. 

  54. Rajini Rao says:

    Update: I came across this news story on early success with clinical trials of hookworm therapy in Australia, for treating celiac disease/gluten allergy:

    (I’ll drop the link in my old celiac disease post as well, so apologies if any of you get notified twice).

  55. Great information!

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