Would You Swallow a Worm to Treat Crohn's?
While helminthic therapy doesn't actually require you to swallow a worm, it does typically involve ingesting the eggs of parasitic worms. It’s not yet an approved form of treatment, but the concept is gaining traction because recent studies have shown promising results.
Helminths are worm-like parasites that are prevalent in rural, agricultural areas of Malaysia and Thailand — places where there also happens to be a very low incidence of inflammatory bowel diseases (IBDs), like Crohn’s. The two species of helminths being studied in association with IBD treatments are the pig whipworm and the human hookworm.
Researchers are working to determine whether helminth infections can be used in people with IBD to modulate the microbiome and immune system from one that’s pro-inflammatory to one that tampers down the immune system, explains Dana Lukin, MD, PhD, director of the Einstein-Montefiore Program for Inflammatory Bowel Diseases and assistant professor of medicine at Albert Einstein College of Medicine in New York City. In animal models, it appears to be possible, which suggests there may be a reasonable therapeutic target therapy for humans, says Dr. Lukin.
In one study published in April 2016 in the journal Science, researchers fed helminths to mice that had the same genetic defect that affects many people with Crohn’s. The parasitic worms were able to alter intestinal flora and promote beneficial microbes in the intestines of the mice, which then led to a reduction in inflammation.
The Hygiene Hypothesis and IBD
“The science behind the idea goes in parallel with the hygiene hypothesis, which has been proposed as one of the potential mechanisms that triggers the inflammatory response,” says Lukin. He explains that in less developed areas, there’s ample exposure to bacterial, parasitic, and other infectious agents that the body learns to adapt to with a healthily functioning immune system. “It’s able to recognize something as a pathogen, deal with it, and then deactivate that immune response,” he says.
But in more developed areas, the environments are typically cleaner and more sterile, and lack exposure to such antigens. This can end up causing a hyperactive immune response upon exposure. Or else, the lack of exposure to potential triggers within the microbiome may, at a future time, activate an immune system that would otherwise have been able to tolerate the bacterial, viral, or fungal trigger, he says.
But just because helminths reduced inflammation in mice doesn’t mean the treatment will translate well in humans. A systematic review published in January 2014 by Cochrane, which focused on two small randomized controlled trials that included 90 patients (36 with Crohn’s disease), didn't provide sufficient enough evidence to draw any firm conclusions about the safety or efficacy of treating patients with Crohn’s.
“The end points of those studies were not rigorously tested,” says Lukin. He suggests that there’s a lot of potential to harness these pathways, but he adds that more rigorous studies in human subjects are necessary to show that ingesting worms can lead to mucosal healing and improvements in noninvasive biomarkers, such as stool calprotectin and C-reactive protein, which can help predict disease activity. “We need more information before we can really recommend that this therapy be used.”
Testing the Parasitic Worms Theory
Not everyone is willing to wait to see if scientists can come up with a drug that produces a similar anti-inflammatory effect as the helminths have shown in animal models. Despite there being insufficient data to say whether the therapy is safe or effective at this time, a number of people with IBD are self-dosing with human hookworm and pig whipworm in hopes of changing the course of their disease.
One Crohn’s patient who took this non-FDA-approved parasitic worm treatment into his own hands — or digestive system, really — was Sean Ahrens, founder of the Crohn’s and Colitis patient-to-patient sharing platform Crohnology. He reported about the experience both on his own sites and in an article published in July 2016 in The American Journal of Gastroenterology titled “Opening (and Swallowing) a Can of Worms to Treat My Crohn’s.” Pig whipworm ova was his parasite of choice.
Ahrens acquired the pig whipworm eggs online through mail-order from a German pharmaceutical company that sourced them from Thailand. As he stated in the article, "being evolved from pigs, the eggs are ultimately rejected by the human body,” so he deemed they were a safer bet than hookworm, which a couple of his friends had tried. Hookworms can live inside the human body for up to two years, and possibly longer, and they can cause intestinal disease. Pig whipworms can only survive briefly inside the human body and they don’t induce disease in humans.
During his experiment, which took place from March through August 2010, Ahrens swallowed the eggs every two weeks and tracked his symptoms, which he reported remained “very active.” In the end, Ahrens couldn’t say for certain whether he felt the helminths made a difference in his disease course.
About two-thirds of the way through his experiment, Ahrens also started following the Specific Carbohydrate Diet (SCD), a diet that minimizes intake of poorly digestible carbs and has been shown to offer therapeutic benefits in some people with Crohn’s disease. Ahrens found that his symptoms did improve about three months after he stopped taking the worm eggs, which was seven months after starting the SCD. Additionally, a colonoscopy in November 2013 showed signs of “remission with no visible inflammation.” But it remains unclear whether the whipworms or the diet, or a combination of the two, may have led to remission for Ahrens. Regardless, his experience underscores just how far some patients are willing to go to find relief from severe Crohn’s symptoms and complications.
“This is not something that would be recommended to the general public,” Lukin emphasizes, adding that extreme caution should be used. “These are parasites, and there are a lot of potential adverse effects to a host like a person, so it’s not advisable to seek treatment just yet.” Still, he does point out that interested patients can look into the possibility of open clinical trials. “That’s the safest way to become involved,” he says.