Ecological Medicine: Can intestinal worms cure us of our modern pandemics?

Hundreds of self-experiments, tens of thousands of worms

In 1976, Jonathan Turton, a British parasitologist was suffering from allergies. Most of the time scientists suffer from maladies just like everyone else. They sniffle. They whine. They ache and curse the universe. They eat the soup that reminds them of their mothers. But sometimes this is not enough. Sometimes a scientist will wake up in the middle of the night with the nagging feeling that she or he is clever enough to do something more. This is when the scientist will start to read through published papers. The scientist will call his friends. The scientist will start to notice things others have missed. Then, every so often, far more often than you might imagine, the scientist will decide one day that he has figured it out, that he knows how to treat what ails him and, rather than wait to do experiments on mice, rather than wait for clinical trials, he does an experiment on himself. Jonathan Turton was one of these scientists and so it was that in 1976 that Jonathan Turton, mostly healthy except for some sniffles, gave himself a hookworm, perhaps to cure what ailed him, perhaps more simply to understand the worms consequences firsthand. The hookworm took up residence in his intestines and, for at least two years, Turton’s hay fever went away.

Now, thirty-nine years later, Bill Parker a scientist at Duke Medical Center, along with colleagues at the University of Central Arkansas, has just published a paper suggesting, on the basis of hundreds of other self-experiments and a review of the literature, that Turton was right. More than that, Parker and colleagues suspect that worms may hold the cure to treating (or even preventing) not only allergies but also dozens of other inflammatory diseases of modernity including not only Crohn’s disease but also Parkinson’s, multiple sclerosis, migraines, anxiety disorders, autism and some cancers, and heart disease. In this telling the parasitic worm is a magic bullet as sweeping in its medical consequences as was the discovery of antibiotics early in the last century. A living bullet.

To understand why this might be the case we need to back up tens of thousands of years. Before our ancestors settled in dense populations they lived as hunter-gatherers. Naked, they gathered fruits. They ate fistfuls of corpulent termites. Insects clung to their fur. These ancestors suffered from ubiquitous parasites and pathogens, particularly worms, of tens of species. Many of the worms colonized the bodies of our ancestors when they accidentally ingested soil contaminated with feces. Others crawled straight through their skin (and then made their way to the lungs where they were coughed up and swallowed).In these ways the lives of our ancestors were similar to every mammal species ever to have existed on Earth. Then things changed.

When our ancestors settled in more dense populations, they became subject to new kinds of pathogens.  Some pathogens came with the domestication of animals; cows and pigs gave us more than meat. Other new kinds of pathogens, pathogens that required the ability to move from one person to another in the cloud of a cough, emerged in response to our growing densities. Others still, such as Chagas disease, found us as we colonized new regions (with new pathogens). The bigger and more geographically widespread the populations of our ancestors grew, the more pathogens and parasites species found a way to live within them. By the time of the renaissance  more than two thousand, TWO THOUSAND, parasite and pathogen species were living on and in humans. Then things changed again, though only for some people.

In the last few hundred years effective public health, medicine and hygiene freed those fortunate enough to be born in developed countries from nearly all of parasites and pathogens. While two thousand parasite and pathogen species can infect humans, the average child in, say, Toronto or London is infected with virtually none of the species. None. None. Zero. Escaped. In temperate, developed, countries we live in a world in which public health, like a sea wall, holds back a tidal wave of human eaters.

But there is more to the story because our immune systems, like those of chimpanzees and other apes (and also every one of our ancestors going back three hundred million years or more), evolved with parasites and pathogens as a conspicuous presence. In the absence of these parasites and pathogens our immune systems are overreactive. They are prepared for wars that don’t come (More than that, our immune systems may have been even more warlike in the years between our first settlements and two hundred years ago, in light of the two thousand parasite and pathogen species–even more ready for a fight, be it in our guts or our hearts). To varying extents, our bellicose immune systems, mismatched with our modern lives are responsible for Crohn’s disease, inflammatory bowel disease, multiple sclerosis, Parkinson’s,  and most of our other chronic modern disease. As I write about in The Man Who Touched His Own Heart, they are even responsible for our heart disease.

There is more to the story than this, more to it in the sense that we have also done other things that make our immune systems warlike. We eat foods that make our immune systems react. We mistreat our gut microbes. We smoke. We are chronically stressed and depleted of vitamin D. But you have a decent understanding of the situation if you imagine a town bully (your immune system) inside your body fighting enemies that never show up. The bully swings wildly. The bully swings and misses. The bully hits you.

This is where the worms come in. Over the last three hundred million years, worms have evolved to find ways to live happily inside their hosts. But hosts fight worms in the same way that the bodies of heart transplant recipients fight donor hearts. The worms are not helpless. Some worms cope by living life fast. They mate and escape before the immune system can throw them out. Others live years, or decades. Those others, the tortoises of the gut, they have evolved chemicals, compounds they produce to suppress the immune systems of their hosts. It was in this light that Turton did his self-experiment.  Turton’s thought that by inoculating himself with a hookworm that the hookworm would live in his gut and produce immunosuppressive compounds which would, in turn, suppress his immune system enough to resolve his allergies. This is, he says, just what happened. But was he right?

In 2011, I wrote a book called The Wild Life of Our Bodies in which I told the story of the status quo in research on the health effects of parasitic worms. At the time one major experiment on the use of worms to treat Crohn’s disease had been conducted. The experiment was viewed as successful (the patients saw remission), but was short term. Another study showed that individuals with Multiple Sclerosis suffered far fewer lesions when accidentally infected with worms (clinical trials are underway). Meanwhile, scientists in Nottingham eagerly searched for the compounds present in the worms in order to turn those compounds (rather than the worms themselves) into a medical treatment. Mostly though the story of worms and health was dominated by a third endeavor, which I wrote about at length in the book, the efforts by a few individuals who had success in using worms to treat their own problems, individuals who did self-experiments. These self-experiments were becoming numerous in precise relationship to the desperateness of individuals (and families) coping with the horrible symptoms of their diseases.

At the time at which I finished the book, the treatments were hopeful but complex, both in terms of our understanding of their effectiveness and the travails necessary to procure them. Then something I never anticipated happened. A researcher named Bill Parker, a man who I chronicled in my book in the context of his radical ideas about the function of the appendix (which now appear to be right), a man who is both clever and unorthodox, got up and walked from one chapter of the book into another, knocking punctuation and pagination here and there as he unraveled the narrative. Bill Parker whose day job is working on organ transplantation, Bill Parker who worked on the appendix as a wild deviation from his day job, Bill Parker started thinking about worm therapies and carried out a study that, were I rewriting my book, would make him not only the feature of a chapter on the appendix but also the conclusion to the story of humans and worms, at least as we understand it today.

Again and again Parker’s genius has proven to be his ability to pair grand ideas with collaborations perfectly suited to testing those grand ideas. When Parker came up with a new idea for the role of the appendix, he found evolutionary biologists he could work with to understand the evolutionary history of the appendix. When he had a new idea about the role of particular antibodies in the gut, he talked to immunologists. And most recently, when he wanted to explore the data embedded (but ignored) in self-experiments with worms,  he found a social scientist, Janet Wilson at the University of Central Arkansas. Together Wilson, Parker, and Parker’s team went about interviewing as many people as they could who had treated themselves or been treated with worms. Apart from assessing the value of worm treatments, this work is important to understanding the unregulated self-treatments going on. But what Parker really wanted to know about was the value.

Their approach was threefold, “First, individuals producing, selling, and/or distributing helminths (“providers”) for self-treatment with helminthic therapy were interviewed. Second, surveys were distributed through social media websites and via helminth providers for individuals self-treating with helminths. Finally, publically available information regarding self-treatment with helminths from a wide range of sources, including books, articles, films, and social media websites was compiled and evaluated.”