When we think of parasitic worms, images of illness, discomfort, and disease typically come to mind. Yet, the story of these creatures—intertwined with humans for millennia—is far more complex and perhaps, surprisingly hopeful. Could the very parasites we’ve spent generations trying to eradicate hold clues to treating the rising tide of autoimmune and inflammatory diseases in the modern world?
A Curious Memory of German Toilets and an Ancient Practice
In the 1970s and 80s, peculiar toilets in Germany left a lasting impression on many visitors. Unlike the familiar water-filled bowls common elsewhere, these toilets featured a dry porcelain platform where waste would rest visibly until flushed away. This design wasn’t a mere eccentricity but linked to a practical health tradition: examining stool for signs of intestinal parasites.
Back then, intestinal worms such as hookworms and tapeworms were common in humans. The presence of these parasites was so frequent that people routinely monitored their stools for worm segments or entire worms. If detected, they would undertake “purges”—using laxatives combined with bitter herbs like wormwood—to reduce worm populations and alleviate symptoms.
This practice faded with modern sanitation and effective anti-parasitic medications, making visible worm infestations rare. Our modern toilets no longer invite us to inspect what passes through us—and parasitic worms have largely been relegated to history.
A Species Apart? The Dangerous Myth of Separation from Nature
Many cultures and religions reinforce the idea that humans are distinct, separate from the natural world. We pride ourselves on cleanliness, hygiene, and technology that distances us from “dirt” and other creatures we consider inferior or dangerous.
Yet, this perceived separation may be harming us. Over the past century, autoimmune diseases such as inflammatory bowel disease (IBD), Crohn’s disease, multiple sclerosis (MS), and asthma have surged dramatically. Conditions once rare now affect millions worldwide, raising urgent questions about the root causes.
Worms and the Immune System: An Unexpected Connection
In the 1990s, gastroenterologist Dr. Joel Weinstock began to explore a radical idea: the very parasites we eradicated might have played a crucial role in regulating our immune systems. He proposed that the absence of helminths—parasitic worms humans evolved alongside—could be linked to the rise in inflammatory and autoimmune disorders.
Weinstock’s research used Trichuris suis, a pig parasite harmless to humans but capable of stimulating the immune system in ways that reduce inflammation. In clinical trials, many patients with Crohn’s disease and ulcerative colitis experienced significant improvement or remission after ingesting microscopic T. suis eggs over several months.
Similar studies followed in multiple sclerosis, hay fever, asthma, and food allergies—with promising results. Scientists in various countries began experimenting with related parasites, including the human hookworm Necator americanus, exploring their potential to rebalance immune responses.
Hookworms: More Than Just a Parasite
British scientist Dr. David Pritchard’s work in Papua New Guinea in the 1980s further illuminated the intriguing relationship between humans and parasitic worms. He observed that local populations infected with Necator americanus—a worm transmitted through contaminated soil—had remarkably low rates of autoimmune and allergic diseases, conditions that were common in highly sanitized Western nations.
To test the theory, Pritchard deliberately infected himself with hookworm larvae. Despite intense itching as the worms entered his skin, he reported no serious harm. Later, he conducted placebo-controlled trials where allergy sufferers ingested either worm-containing capsules or sugar pills.
The results astonished many: those who received the worms experienced dramatic relief from allergies and asthma symptoms. The immune-modulating effects of hookworms seemed to calm the overactive immune responses underlying many autoimmune diseases.
The Modern Quest: Reintegrating Ancient Allies?
Today, “helminthic therapy” is emerging as an experimental treatment in clinics worldwide. Some patients with chronic autoimmune conditions seek out controlled worm infections to regain immune balance. The therapy’s appeal lies in its natural approach—reconnecting the human body to organisms it co-evolved with, rather than suppressing immune function with pharmaceuticals.
Yet, this approach is not without challenges. Researchers must carefully study safety, dosing, and long-term effects before recommending it broadly. Still, the growing body of evidence suggests that worms are more than just parasites—they may be vital partners in our immune ecosystem.
We Are Not Separate; We Are Connected
Science now confirms what many indigenous and traditional cultures have long known: humans are not isolated entities but integral threads woven into Earth’s intricate web of life. The DNA within us contains far more microbial and parasitic material than human genetic code alone.
Our attempts to remove ourselves from nature’s complexity—through relentless sanitation, chemical use, and disconnection from “dirt”—may have unintended consequences. The rise in autoimmune disorders might be one such consequence, a signal that we have disrupted delicate biological relationships essential for health.
Conclusion: Rethinking Our Relationship with Parasites
Parasitic worms, once seen solely as enemies to be eradicated, are now gaining recognition as potential healers in disguise. Their millennia-long coexistence with humans suggests a complex biological dialogue—one that might help explain and even treat some of today’s most challenging diseases.
Perhaps it’s time to reconsider our place within nature, embracing a more holistic view where parasites and humans coexist in balance. In doing so, we may find solutions to modern epidemics hiding in the most unexpected places—the ancient allies within our own bodies.
Thom Hartmann is a bestselling author and progressive radio host. This article is adapted with permission from his Substack, The Wisdom School: What It Means to Be Human.
