Helminthic therapy is a relatively new treatment which takes the form of deliberate infection with the larvae or eggs of specially domesticated, benign, mutualistic intestinal worms.
Viewed from a medical perspective, this therapy is an experimental form of immunotherapy used in the treatment of chronic inflammation, autoimmune disease and other immunological disorders including allergy. It can also be seen simply as a form of probiotic treatment, using tiny animals instead of bacteria to reconstitute and enrich a depleted intestinal biome.
The legal position concerning helminths is still uncertain and untested in many countries, but is clearer in the US, where hookworms, whipworms and rat tapeworms are currently classified by the Food and Drug Administration (FDA) as biological agents (i.e. drugs), as defined in Section 351 of the Public Health Service Act, and subject to an Import Alert.
Although it does not yet have FDA approval for use in medical practice, helminthic therapy is (almost) legitimate medicine, with considerable supporting research published in peer-reviewed journals.
“”What was a costly and sometimes risky venture into the unknown, undertaken by only a few 10 years ago, is rapidly becoming a readily available and well-established resource currently used by thousands of individuals.
|—Cheng et al, 2015|
“”The results strongly support previous indications that helminth therapy can effectively treat a wide range of allergies, autoimmune conditions and neuropsychiatric disorders…"
|—Liu et al, 2016|
“”Twenty years from now everybody is going to have a helminth, and no insurance company will begin to cover you if you don't have your helminths … We're very confident in the science, that every single human being needs a helminth. It's part of our biology.
|—William Parker, 2016|
“”… we need to embrace the view that helminths are a necessary component of the ecosystem of a healthy body, and that helminths should be cultivated for population-wide biota restoration.
|—Villeneuve, et al, 2017|
The largest reference work on this subject is the Helminthic Therapy Wiki. This contains full details about all four helminth species that have been domesticated for use in therapy and the companies that supply them, as well as links to hundreds of relevant scientific papers, media articles and anecdotal accounts by those who are self-treating with helminths.
- The most famous example of this is that "hookworms cure asthma". And it turns out that hookworm "therapy" has at least been shown to be harmless.
Helminth infestation is probably effective against asthma and other allergic reactions because, by necessity for their own survival, they induce immunosuppressive activity in the host.
- Arguably, medicinal leeches (various species, for instance Hirudo medicinalis), which, although not 'helminths', are annelid worms used by doctors because of their anti-coagulation effects.
Organisms unsuitable for therapeutic use
- The giant roundworm (Ascaris lumbricoides — see illustration) has been shown to sometimes help against asthma, atopic dermatitis and similar allergic reactions, but this is not a suitable species for therapeutic use.
- The beef tapeworm (Taenia saginata) has been used for weight loss. The "logic" behind this was that the tapeworm would reach your intestine and absorb the contents of the food you eat. This would allow you to eat as much as you want, as most of the calories and fat from the food would be going to the tapeworm(s), not to you. The problems are many. The tapeworm wouldn't "claim" most of your calorie intake. If you have a limited diet, the tapeworm will probably result in malnutrition. The tapeworm will also hijack several micronutrients. Although most beef tapeworm infections have no symptoms, and, given its size, this organism will no doubt excrete/secrete a large quantity of beneficial immunomodulatory molecules, there are times when the tapeworm can do real damage to its host, who may also eventually pass on the infection to others.
It should be noted that numerous phyla of worm exist. Taenia saginata, mentioned above, is of the phylum Platyhelminthes (flatworms), which has not been used to date in helminthic therapy. Ascaris lumbricoides mentioned above is of the phylum Nematoda (roundworms), some members of which have been used in the therapy and are the subject of some of the peer-reviewed research described herein, as is Trichuris suis, the pig whipworm, which has also been tested for medicinal value. Despite broad similarities in appearance, the worms vary widely in their own biology as well as in their interaction with the human body.
- Overcoming evolutionary mismatch by self-treatment with helminths: current practices and experience.
- Practices and outcomes of self-treatment with helminths based on physicians' observations.
- Hooked on hookworms (and other parasites).
- Evolution of the hygiene hypothesis into biota alteration theory: what are the paradigms and where are the clinical applications?
- Helminthic Therapy Wiki.
- Experimental hookworm infection: a randomized placebo-controlled trial in asthma.
- Reduced helminth burden increases allergen skin sensitization but not clinical allergy: a randomized, double-blind, placebo-controlled trial in Vietnam.
- Safety of hookworm infection in individuals with measurable airway responsiveness: a randomized placebo-controlled feasibility study.
- Helminths and immunological tolerance
- Helminthic Therapy Wiki: Ascaris lumbricoides.
- Yes, people really did that.
- Helminthic Therapy Wiki: Helminths, appetite and body weight.
- Helminthic Therapy Wiki: Therapeutic Helminths