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Protective Parasites: Eating the Pain Away

by Ellen Kruczek

Good news: a person with a debilitating inflammatory disease carries parasites! That’s not a sentence you would expect to hear, but it is one that thousands of patients around the world want to hear. These patients are a part of the currently unregulated medical movement called helminthic therapy, which involves treating those with inflammatory diseases and disorders with helminthic parasites.

Helminthic parasites are the reason that your mom told you to wear shoes when playing outside, particularly if you grew up in the southern United States (U.S.). Helminths, like whipworm and hookworm, can enter a person’s skin through prolonged exposure to contaminated soil. Their larvae can also be ingested from contaminated water or food, which is exactly what some patients are doing on purpose across the U.S.

Dr. Joel Weinstock of Tuft’s University proposed that humans used to have more parasites in their intestines that played a role similar to that of modern bacteria. Today’s bacteria help break down nutrients and create a stable environment for the stomach and intestines in order to maintain themselves. Similarly, helminthic parasites release certain immune “relaxers,” which work to prevent the immune system from initiating excessive responses in the gut. Not all parasites are good for you, but simple ones, including the pig ringworm have little negative effect.

For example, most parasites are believed to suppress Th1 immune cells and either promote or suppress Th2 immune cells. Too many Th1 cells can promote autoimmune diseases, like some diabetes. Conversely, too many Th2 cells can cause allergies and inflammation. Parasites suppress and promote Th2 cells to minimalize inflammation, particularly where the parasites are located--this is why parasites can live for years in humans. The body barely knows they are there because they release these relaxants. Helminthic worms are especially good at pretending they do not exist because their only rare harmful side effect is anemia, the shortage of healthy red blood cells. With that in mind, arguably, mothers who make their kids wear shoes to prevent them from picking up parasites outside might be fueled more by social stigma than preventing those harmful side effects. Most people cringe when they look at a tapeworm. However, it is not tapeworms being proposed for parasite therapy.

New York Times writer and author of the book “An Epidemic of Absence,” Moises Velasquez-Manoff knows parasite therapy well. His book focuses on how our bodies have poorly reacted to the absence of certain bacteria and parasites, and that’s the core of parasite therapy. He also explains limitations of the type of therapy, and why doctors across America are not scrambling to this treatment that The Guardian regards as “a miracle.”

“The problem with parasite therapy is that it hasn't been proven to work in a scientifically rigorous way,” Velasquez-Manoff said. No large scale study has confirmed what the Internet raves about. Online communities, such as the Facebook group of self-treaters called Helminthic Therapy Support have over three thousand members. Articles from the New York Times, The Guardian and Scientific American all highlight its benefits. Despite what troves of websites and articles insist, helminthic therapy is not a miracle. At least not yet.

Dr. Helena Helmby, from the London School of Hygiene and Tropical Medicine, has hope. In her 2015 article for BMC Immunology, she says, “Some promising data has been achieved using human helminth therapy but many questions remain to be investigated…” The questions she proposes are: How long patients should be infected? Which helminthic worms should be used? Which helminthic proteins affect the body?

Researchers, such as Dr. Alex Loukas of James Cook University in Australia endeavors to answer some of these questions. Loukas has isolated certain helminth excretory proteins that prevented inflammatory asthma in mice. However, human trials at this level of understanding might be far off, or might never come at all. Velasquez-Manoff is confident that online communities will continue to promote self-infection, and that the Internet success stories will continue. As with most science, the process is slow. 

Inflammation plagues millions of Americans every year. It plays roles in bowel disorders, diabetes, arthritis, allergies and many more. There are millions of dollars poured into maintaining comfort during painful inflammation. Those people might feel they are running out of options. Parasites could be a real option in the medical world. Despite that promise, the treatment is still in the larval phase. Only more research will tell if this promise can be a reality.