Introduction to helminthic therapy
Helminthic therapy involves the deliberate hosting of a controlled number of carefully selected, benign intestine-dwelling nematodes (worms) known as helminths. This is a type of organism with which people living in developed countries have gradually lost contact during the past 150 years as a result of the increasing use of shoes and toilets, and of changes in medical, agricultural and food preparation and storage practices.
Viewed from a medical perspective, helminthic 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 another form of probiotic treatment, using tiny animals instead of bacteria, to reconstitute and enrich a depleted intestinal biome.
A brief history of helminthic therapy
Helminths are among the heirloom species that humans inherited from our primate ancestors and which have continued to coexist and co-evolve with us over millions of years to the extent that we are now incomplete without them and depend on their presence for the optimal functioning of our immune system. These symbiotic organisms train the developing immune system in infancy and continue to regulate immune function throughout adulthood for as long as they remain with us.
Evidence pointing to the importance of helminths for human health began to emerge in the 1970s, and included a report of higher levels of allergic disease in urban communities than in rural indigenous areas where levels of helminth infection were much higher.
By 1990, it had become clear from further scientific studies that, while autoimmune, inflammatory and allergic conditions have escalated in developed countries during the past century, they have remained much less common in parts of the world where helminths are still prevalent. It was this realisation that gave rise to the idea of reintroducing helminths into patients who have developed one or more of these conditions, in the hope that this intervention might rebalance their immune system and restore their health. The first indication that this might be an effective approach had already appeared in the Lancet in 1976, when a researcher had reported putting his own seasonal allergies into remission by infecting himself with hookworms.
Researchers began to consider the importance to health of what has become known as the microbiome, and the theories formed by these pioneers have been refined through several stages, each being given a new title, viz. the Hygiene Hypothesis, the Old Friends' Hypothesis and, most recently, Biome Depletion Theory and Evolutionary Mismatch Theory.
During this process, helminths have been identified as being of special significance, and they are now considered to be keystone species of the human multibiome, with profound importance for health. So much so that there are calls for them to be employed not only as a treatment for established disease, but also as a preventative to help eliminate the epidemics of allergic, inflammatory and autoimmune diseases that are today afflicting the populations of developed countries, and possibly also to offer protection against many degenerative diseases such as atherosclerosis, diabetes and cancer.
Many members of the medical profession remain sceptical about the use of live helminths, and some are overtly hostile, with the result that the use of these organisms in medical practice is being delayed until validated by clinical studies. Where helminths have already been the subject of clinical trials, most of these have employed methods that were designed to test pharmaceutical products and are unsuitable for the assessment of a natural therapeutic, especially one whose beneficial effects do not materialise for at least 12 weeks - the maximum period typically used in drug trials - and, in a few cases, have taken as long as 19 months.
As a consequence of these factors, millions of patients are being forced to continue to suffer the often devastating effects of immunological disorders, along with the frequently serious side effects produced by many of the pharmaceutical therapies currently prescribed to treat them. And this is in spite of the fact that four helminth species have already been identified as suitable and safe for use in therapy, are available for purchase via the internet and are currently being used by an estimated 7,000 individuals.
A wide range of inflammation-related conditions, allergies, autoimmune diseases, and even neuropsychiatric disorders such as depression, anxiety, migraine headaches, bipolar disorder and Parkinson’s disease have been effectively ameliorated by self-treaters using the available therapeutic helminths. 
While citizen scientists continue to refine the use of live helminths, medical researchers have their sights set on the creation of drugs employing helminth-derived molecules, but these pharmaceutical products are still many years away, and if and when they do become available, some, if not all of them, are likely to present adverse side effects, as are seen frequently with other single molecule drugs. Moreover, some researchers have suggested that no wormderived pharmaceutical will ever match the efficacy of a live worm.
Although acceptance of helminthic therapy by the medical establishment is currently being hindered by the strong pharmaceutical bias of modern Western medicine, it is nevertheless predicted to become an essential part of healthcare in the future.
It is recommended that anyone interested in joining the growing ranks of helminth hosts should read this entire document very carefully, along with the material at the links within it. This will help to increase the likelihood of a satisfactory outcome from using the therapy, and will save members of the online groups having to respond unnecessarily to questions that are answered here.
- HD - the rat tapeworm, Himenolepis diminuta
- HDC - the cysticercoids of the rat tapeworm, Himenolepis diminuta
- HK - hookworm, usually referring to the human hookworm, Necator americanus
- HT - helminthic therapy
- HW - hookworm, usually referring to the human hookworm, Necator americanus
- NA - the human hookworm, Necator americanus
- TS - the porcine (pig) whipworm, Trichuris suis
- TSO - the ova (eggs) of the porcine (pig) whipworm, Trichuris suis
- TT - the human whipworm, Trichuris trichiura
- TTO - the ova (eggs) of the human whipworm, Trichuris trichiura
- WW - whipworm, usually referring to the human whipworm, Trichuris trichiura, but possibly also Trichuris suis
Helminthic therapy science
The following papers provide an overview of the therapeutic potential of controlled colonisation by benign helminths, and would be suitable resources to give to a doctor or anyone else who is unaware of the evidence and rationale for helminthic therapy. The first two papers provide validation for the practice of self-treatment with helminths.
- Practices and outcomes of self-treatment with helminths based on physicians' observations
(2016) The first study to examine, through the eyes of their physicians, the practices and experiences of individuals who are self-treating with helminths.
- Overcoming Evolutionary Mismatch by Self-Treatment with Helminths: Current Practices and Experience
(2015) This study probes the methods and outcomes reported by individuals who are self-treating with helminths and is an ideal basis for the education of physicians who need to discuss helminthic therapy with their patients.
- Ecological Medicine: Can intestinal worms cure us of our modern pandemics?
(2015) An excellent article in its own right, this is also a good introduction to number 2.
- Evolutionary biology and anthropology suggest biome reconstitution as a necessary approach toward dealing
with immune disorders (2013) Explains how the modern pandemics of autoimmune, inflammatory and allergic diseases are due to the loss of species - especially of helminths - from the human ecosystem.
- [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3744090/?report=classic Helminth–host immunological interactions: prevention and control of immune-mediated diseases
(2012) Summarises the science underpinning helminthic therapy.
- Reconstituting the depleted biome to prevent immune disorders
(2010) Explains why replacing absent "old friends" may be the only reasonable therapy for a wide range of immuneassociated disorders, including allergy, autoimmunity and autism.
- Distribution of autoimmune disorders and helminths
A graphic showing that autoimmune diseases are much less common in areas where helminth infestation is high.
For a full list of scientific papers and articles from the media documenting the history and development of helminthic therapy from its beginnings up until the present day, see the document, [http://www.foodsmatter.com/natural_medicine_comp_therapies/helminthic_therapy/articles/helminthic-therapy-in-science-and-the-media.pdf Helminthic Therapy in Science and the Media].
- should not cause disease in humans at therapeutic doses
- should not be a potential vector for other parasites, viruses, or bacteria
- should not cause long-term symptoms in humans at therapeutic doses
- should not alter its behaviour in patients with depressed immunity
- should not be easily transmissible from the host to other people
- should not be able to reproduce in a host, and thus prevent dosage from being controlled
- should be easily eradicated from the host, if required
- should be compatible with commonly used medications
- should be easy to administer
- should be amenable to production in large numbers
- should be amenable to storage and transportation
There are currently four types of helminth available commercially for use in self-treatment.
- Pig whipworm, Trichuris suis (TS)
Introduced for therapy in 2004 Sold as ova (TSO)
- Human hookworm, Necator americanus (NA)
Introduced for therapy in 2006 Sold as larvae
- Human whipworm, Trichuris trichiura (TT)
Introduced for therapy in 2009 Sold as ova (TTO)
- Rat tapeworm, Himenolepis diminuta (HD)
Introduced for therapy in 2011 Sold as cysticercoids (HDC)
Selecting a therapeutic helminth
The scientific evidence
There have been no head-to-head clinical trials comparing any of the currently available therapeutic helminths, and there may never be any, due to the extremely high cost of mounting such studies and the lack of incentive for anyone to fund them. There is also little scientific evidence for the efficacy of individual helminths.
In the groundbreaking Correale and Farez study of 2007 in patients with multiple sclerosis, all the helminthinfected subjects benefited, even though they had 5 different species of worm between them. Therefore the species of worm may not make as big a difference to the outcome of helminthic therapy as might be imagined.
The only organism to be studied in the treatment of autoimmune disease, in well-designed trials at therapeutic doses, is TSO, which has been shown to be safe and effective in ulcerative colitis, promising in the management of Crohn's disease, as well as in the treatment of relapsing-remitting multiple sclerosis and in dampening allergic airway hyper-reactivity. TSO has also shown significant results in 70% of subjects with the inflammatory subtype of autism spectrum disorder (I-ASD) who took TSO in its original pH2.7 form.
Several other trials of TSO were conducted by the now defunct company, Coronado Biosciences, prior to the termination of its research programme early in 2015 following what appeared to be disappointing results. However, the apparent failure of these trials may have been due to poor trial design, including an inadequate assessment period of only 12 weeks and, especially, the insistence by the researchers on using a novel formulation of TSO with a higher pH than the product that had been employed successfully in previous studies and used to good effect by self-treaters for more than a decade. , 
The first trial of the hookworm, NA, to use a realistic dose and duration of colonisation was completed in early 2016 at Nottingham University in subjects with Multiple Sclerosis, but the results from this trial had not been published when this document was last updated.
There have been no clinical trials using the other available therapeutic organisms, TTO and HDC, although there is a detailed case study of an individual with ulcerative colitis who experienced almost complete remission of his symptoms after self-infecting with TTO, and a further case study showing several indicators of mucosal and systemic immune modulation following self infection with TTO.
The anecdotal evidence
While data from clinical trials is still limited, the anecdotal evidence gathered by the self-treaters who have pioneered helminthic therapy for more than a decade is already significant and compelling. ,  Apart from the study at the second of these links, there is little recorded anecdotal evidence for TSO and HDC, largely because users of these two organisms, and especially TSO, have been much less active on helminthic therapy social media sites. NA has been discussed extensively online since 2007, and TTO since 2009, originally on the Yahoo Helminthic Therapy Forum and, more recently, in the Facebook Helminthic Therapy Support Group.