RENEE MONTAGNE, HOST:
Now we turn to an unusual trend in medicine. People are trying to treat autoimmune problems, like asthma, allergies and Crohn's disease, with an unlikely tool - worms that live in your gut permanently. And perhaps this is a good moment to put down your cereal spoon, as NPR's Michaeleen Doucleff reports.
MICHAELEEN DOUCLEFF, BYLINE: Moises Velasquez-Manoff is a science writer in Berkeley. And for years, people have told him how great worms are for treating horrible autoimmune diseases. People said they were completely cured. So Velasquez-Manoff was curious.
MOISES VELASQUEZ-MANOFF: So, like, what did people feel like - is what I wanted to know - with these things living in their body?
DOUCLEFF: Oh, I forgot to mention, Velasquez-Manoff has no hair. He has an autoimmune disease called alopecia, and he thought hey, maybe the worms could fix that.
VELASQUEZ-MANOFF: So I decided to test that proposition.
DOUCLEFF: He went down to Mexico, bought 30 hookworms and let them infect him.
VELASQUEZ-MANOFF: They basically ride your bloodstream back through your heart, into your lungs...
DOUCLEFF: Where they hang out for a while.
VELASQUEZ-MANOFF: ...And they crawl out your lungs, through your stomach and end up in the small intestine.
DOUCLEFF: Where they bite onto the intestinal wall and start sucking blood, a few drops a day. At that point, the worms do something amazing.
P'NG LOKE: The worms suppressed immune systems. That's the really fascinating thing.
DOUCLEFF: That's P'ng Loke, an immunologist at NYU School of Medicine. He says the worms don't shut down the immune system completely, just a little bit so that the immune cells won't attack the worm. But this suppression can help with something else. It keeps the immune system from getting out of control and attacking the body.
LOKE: Yeah. And, I mean, that's really important. If - you know, if you think about it, the worst thing that you want is an immune system that's out of control.
DOUCLEFF: Then you get autoimmune problems - Crohn's disease, allergies, even multiple sclerosis. So the hypothesis is that worms could possibly reverse these problems by damping down the immune system.
The idea was so promising that back in 2011, a pharmaceutical company decided to test it in clinical trials. Coronado Biosciences put together about six large studies. Stephen Hanauer is the medical director of the Digestive Health Center at Northwestern University. He was involved with one of the trials. He says the first study to finish was a big one in Europe. It looked to see if whipworms helped with Crohn's disease. The bottom line...
STEPHEN HANAUER: The proportion of patients who improved with the worms was no different than the proportion of patients who improved with placebo.
DOUCLEFF: The worms didn't work. They were so ineffective that Coronado canceled its other trials, its stock plummeted and, eventually, the company changed its name and its focus. Hanauer says other trials didn't go well either.
HANAUER: The control trials, thus far, in a variety of different diseases, including childhood allergies and asthma, have not been positive.
DOUCLEFF: Back in Berkeley, Velasquez-Manoff got his own results before the news came out about these big trials. He has written about them in a book exploring the therapy. He says a few months after he took the hookworm...
VELASQUEZ-MANOFF: My hay fever was almost completely gone, like, just gone, gone, gone.
DOUCLEFF: And his hair?
VELASQUEZ-MANOFF: And then I had, like, little bit of, like, a peach fuzzy hair growing here and there on my body.
DOUCLEFF: You did?
DOUCLEFF: Wow, it's so interesting.
VELASQUEZ-MANOFF: And then suddenly, it's like, one day, the whole thing reversed.
DOUCLEFF: His hay fever came back. The hair stopped growing, and having the worms in his body wasn't pleasant. He had diarrhea and cramps as long as the worms were inside of him.
VELASQUEZ-MANOFF: I never got back to feeling completely normal for that year.
DOUCLEFF: Is this something that you would use as a therapy?
VELASQUEZ-MANOFF: No. The way I thought of it was, would I give this to my kids? And the answer is pretty easily and obviously, [expletive] no. Like, I wouldn't want them to feel this way.
DOUCLEFF: Michaeleen Doucleff, NPR News.
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