Throughout evolutionary history humans have coexisted with intestinal worms known as helminths. It is thought that having been forced to tolerate helminths, our immune systems have developed over millennia to become dependent upon their presence. Helminths have been proven to be potent immune regulators through secreted/excreted molecules that enable them to evade their hosts defences and survive by stimulating production of anti-inflammatory immune cells. During our long and constant coevolution with helminths our immune systems have developed to expect their presence and rely upon their immune modulating influence in order to function properly.
Over the past 100 years the human environment in the industrialised world has changed beyond recognition. Urbanisation, improved sanitation, modern sewerage systems, vaccination programmes and antibiotic use have massively reduced incidence of what were once widespread and devastating infectious diseases. At the same time, however, we have lost contact with many symbiotic organisms that the human body should naturally harbour.
In 1989 Dr David P. Strachan published an article in the British Medical Journal in which he observed that allergic diseases were less common in children from large families and linked this to increased exposure to infectious agents in childhood [link]. The theory that emerged from his observations has become known as the Hygiene Hypothesis. This concept has since developed into the Old Friends Theory which states that the human body has an internal ecosystem or biome which should include a large and varied number of micro and macroorganisms in order for the immune system to properly function. Due to rapid changes in the modern urbanised environment, we have lost contact with many of these necessary organisms and this has damaged the development of our immune systems leading to unchecked inflammatory responses that result in allergic dysfunction and autoimmune diseases.
The Hygiene Hypothesis / Old Friends Theory has now become one of the main theoretical frameworks used in the study of immune disorders and has naturally led to the idea that re-introducing helminths or helminth derived products into the human biome could help immune dysfunction of all kinds.
Over recent decades there have been a wealth of studies into the immunoregulatory effects of helminths, both in animal and human subjects. Here are just a few:
In 1999 Professor Anne Cooke treated NOD (Non Obese Diabetic) mice with helminths with the result that they blocked the development of type 1 diabetes. [link]
In 2002 researchers at Harvard Medical School found that mice predisposed to anaphylaxis from peanut exposure had a greatly diminished response when treated with helminths. [link]
In 2003 researchers at the University of Iowa found that exposure to helminths decreased the colonic inflammation that leads to Crohn’s disease in mice. [link]
In 2007 researchers at Trinity College, Dublin, found that in mice predisposed to develop colitis, helminths prevented the onset of the disease. [link]
In 2012 Margaret Harnett and colleagues at Glasgow University found that molecules secreted by helminths significantly inhibit the progression of rheumatoid arthritis in mice. [link]
Also in 2012 researchers at the University of California found that helminth treatment resulted in remission of symptoms in 4 out of 5 rhesus monkeys with ICD (a condition similar to ulcerative colitis in humans). [link]
In 1993 Dr Neil Lynch found that treating children from a Venezuelan slum for parasitic worms precipitated the development of allergy, whereas untreated children remained allergy free. [link]
In 2004 Dr David Pritchard was one of the first to pioneer the use of Necator americanus hookworms in treating immune dysfunction. During field work in Papua New Guinea Dr Pritchard had observed that local people colonized with hookworm were less likely to suffer allergic and immune disorders. The success of an initial experiment involving self-colonization led to a 2006 study at Nottingham University with 30 participants, 15 of whom received 10 hookworms each. The results showed that those who had hookworms began to experience a lower inflammatory response, and that their immune reactions became suppressed compared to those on the placebo. [link]
Dr Pritchard reported that “Many of the people who were given a placebo have requested worms, and many of the people with worms have elected to keep them”.
In 2010 Dr Pritchard published the results of a study conducted in Vietnam involving 1487 children in a rural helminth endemic region. It found that those given anti-helminthic treatment over a 12 month period to reduce their worm burden suffered an increase in allergen skin sensitisation. [link]
In 2005 Dr Joel Weinstock and colleagues at the University of Iowa carried out a study using helminths on 29 patients with active Crohn’s disease. 23 patients (79.3%) responded to the treatment with 21 (72.4%) going into full remission. In the same year they also published results of a trial that found helminths to be a safe and effective treatment for patients with active ulcerative colitis. [link]
In 2007 Dr Jorge Correale et al published the results of a 5 year study into the effects of helminth colonization in patients with multiple sclerosis which found that those hosting helminths experienced significantly reduced symptoms of MS compared to patients without helminths. [link]
In 2014 Dr John Croese collaborated with scientists at the James Cook University in Queensland, Australia to trial the effects of hookworm in patients with Celiac disease. Subjects were inoculated with 20 Necator americanus larvae and exposed to escalating gluten challenge over 12 months. By the end of the trial subjects were able to consume a medium-sized bowl of spaghetti with no ill effects, a meal that would normally have triggered diarrhea, cramps and vomiting. All subjects chose to keep their worms after completing the trial. [Link]
Jame’s Cook University’s Professor Alex Loukas commented that “This trial has confirmed hookworms as our choice of parasite for clinical applications,”
Research by Dr Rick Maizels of Edinburgh University has identified part of the biological explanation for helminth’s ability to dampen down an overactive immune response. He found that mice hosting parasitic worms created more regulatory T cells which modulate the immune response by secreting compounds that counteract the inflammatory effects of other immune cells. [link 1, 2]
He explained that “There’s a lot of evidence that allergy is the immune system going a little over the top. The worms are just turning down the volume.”
At present there are a number of clinical trials ongoing into Helminthic Treatment in various immune related diseases. In December 2013 Coronado Biosciences presented interim data at the American College of Neuropsychopharmacology annual meeting for their trial into helminth colonization in autism patients. After 12 weeks of double-blind, randomized, placebo-controlled, cross-over study, patients with helminths saw a statistically significant reduction in autistic behaviors. [link]
The most compelling evidence for the success of Helminthic Treatment, however, can be seen outside of the lab environment. Over the last 10 years as more people have heard of the startling immunoregulatory abilities of helminth worms, many have self-colonized to treat a myriad of immune-related conditions. There is estimated to be an astounding 80% success rate amongst the Helminthic Treatment community and many credit their old friends with having saved them from a life of crippling disease and dependence upon pharmaceuticals with ever worsening side effects. You can read many accounts and general discussions about Helminthic Treatment on the Yahoo and Facebook HT support groups:
The Facebook HT Support Group is a vibrant and friendly community of HT users which also has a helpful Files section where answers to many of the most frequently asked questions regarding the treatmant can be found.