Official caution on parasite therapy has been overtaken by events. Scientists need to catch up
IF YOU were to draw a world map of severe immune disorders and superimpose it on a map of infections with parasitic worms called helminths, you would see a very clear pattern. Where immune disorders are common helminthic infections are rare, and vice versa.
According to the hygiene hypothesis, this is because living in an ultra-clean environment deprives the immune system of necessary exposure to pathogens and parasites. If that鈥檚 true, then reconciling people with their long-lost worms could help to reset malfunctioning immune systems. That鈥檚 exactly what some scientists have been investigating since the 1990s.
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But helminthic therapy has not got very far. There has never been a full-scale clinical trial and most published studies recruited only a handful of people. Pig whipworm has been granted the status of Investigational New Drug in the US, but given that it usually takes hundreds of millions of dollars and more than 10 years to get a drug to market, worm therapy is still a distant prospect.
No wonder some people are taking matters into their own hands: breeding the worms at home, swallowing eggs isolated from faeces or buying worms from companies that have sprung up to meet the demand (see 鈥淐itizen scientists eat worms to treat disorders鈥�). The US is so concerned about this 鈥渃itizen science鈥� movement that it has made it illegal to sell helminths for therapy.
聯Some people are taking matters into their own hands, swallowing eggs isolated from faeces聰
If there are more than a few scientists intrigued by worm therapy and plenty of volunteers to swallow the worms, why aren鈥檛 there more clinical trials? The problem is onerous regulation.
The caution is understandable: helminths are living organisms, not chemicals that can be precisely dosed, and they can cause illness. But given that there are already hundreds of people experimenting with therapies, it is clear that caution has been overtaken by reality.
It is surely time to loosen the regulations and encourage fruitful collaborations between scientists and citizens. That would at least dissuade the do-it-yourself worm therapists who potentially endanger themselves and their friends. It may even deliver much-needed progress in some of the most expensive and intractable health problems of our age.