Are We Killing Ourselves with Cleanliness? As Number of Allergy Sufferers Soar, Potential Cures Are More Radical

In a Boston hospital, people are eating whipworm eggs.

Too small to see, they're swigged in cups of tasteless, odorless clear liquid. Once swallowed, they lodge in the gut and produce larvae. They're parasites, known clinically as Trichuris suis. Are they the next big thing in allergy relief?

Pathologist Marie-Helene Jouvin, who launched this study at Beth Israel Deaconess Medical Center with allergist/immunologist Mariana Castells, hopes they are -- and the sooner the better, as America's allergy rate is soaring. According to the Centers for Disease Control and Prevention, the number of young Americans with food allergies soared nearly 20 percent in the last decade. Eight percent of children under six now have food allergies. The number of adults with allergies has risen too.

The Boston worm study stems from a scientific hot potato called the hygiene hypothesis, which holds that growing up in developed nations enfeebles our immune systems. When it's not constantly battling dangerous bacteria, "the immune system doesn't know what to fight against," Jouvin says, "so it fights against stuff that isn't supposed to be dangerous, like food.

"As the human immune system matures, normally it learns how to differentiate what is not dangerous from what is dangerous. If you raise children in too clean of an environment, this distinction is missing."

In other words, we're killing ourselves with cleanliness.

Allergies are far more common in rich nations than in poor ones. Hygiene hypothesists believe that's because people in poor countries are riddled with parasites.

Studies in Africa and South America have tested groups of parasite-infected people and found them to have few or no allergies. These people were then treated with vermifuges. Once they became parasite-free, they developed allergies, Jouvin says.

"We don't know precisely how it works, but parasites have developed this very fine mechanism that allows them to survive in a host's body without killing the host and without the host killing them. The presence of parasites in the body acts on the immune system and somehow avoids an allergic reaction."

Because Trichuris suis flourishes in pigs' bodies but not human ones, the larvae that hatch after the eggs are ingested never fully mature in human subjects, who thus never become infected. The Boston study won't be completed for another few years; if it succeeds, FDA approval would be sought for Trichuris suis ova, aka TSO.

"The eggs are the medicine," Jouvin says. "It's very easy, a clear liquid. You just drink it."

"This idea that you can infect yourself with these things so that your immune system gets too tied up with parasites to worry about allergens" is gaining traction, "but it's very radical," says allergist Andrew Engler, director of the Allergy and Asthma Clinic in San Mateo, California.

It's not as radical as the remedy that integrative-medicine guru Andrew Weil aired at the Psychedelic Science in the 21st Century conference in San Jose last April. Having been terribly allergic to cats all his life, Weil took LSD one day at age 28. While he was tripping, a cat jumped into his lap. For a split second, Weil froze. Just being near cats had always made his eyes itch and his nose run. If cats licked him, he'd always broken out in painful hives. But not this time: "I started petting the cat. I began playing with the cat. The cat licked me. I had no reaction to the cat. I have never had a reaction to a cat since -- and that was almost 40 years ago. Now, that's pretty special. As a physician, I would love to know what happened there, and I would love to know how to make that happen for other people."

The medical community isn't investing tons of time or money in the wider applications of LSD. Nor does it consider acid -- or anything else -- an allergy cure. Symptom-soothers flood the market. Desensitization studies involving peanuts and insect venom offer hope, but nothing has yet been clinically proven to render once-allergic human bodies no longer allergic.