Man Doses Himself With a Parasite for Intestinal Problems

Dec. 2, 2010— -- Catching an intestinal parasite is not usually considered desirable, but for a California man with severe gastrointestinal problems, dosing himself with worms was the answer to his prayers.

After reading preliminary research that suggested a whipworm found in pigs could help those with ulcerative colitis, the 34-year-old patient tracked down and ingested eggs from Trichuris trichiura, a similar roundworm that infects humans, in hopes of easing his own colitis.

After a few months, the abdominal pain and bloody diarrhea associated with the patient's ulcerative colitis improved dramatically, and after a second "booster" dose of worm eggs, he remains in remission more than four years later.

In hopes of better understanding how certain parasitic worms can be used to heal, doctors at New York University Langone Medical Center ran extensive testing on this man, the results of which were published Wednesday in Science Translational Medicine.

"Essentially this patient has been in remission for several years, with no other medication. For this individual, the goal is to remain infected for the rest of his life, but it's hard to know if that's a viable strategy for everyone. We don't have a good understanding of the risk," said P'ng Loke, assistant professor of medical parasitology at NYU Langone Medical Center and lead author of the study.

Treating colitis with worms is not new. The first human trials using pig whipworm took place in 2005. and this worm is being developed as a possible colitis vaccine, said Dr. Joel Weinstock, who pioneered this research while at the University of Iowa Carver College of Medicine. But Loke's case study may shed more light on how these worms protect and heal the colon.

Researchers found that the parasite works by inciting a specific type of immune response. In an attempt to rid the body of the worms, the immune system signals the body to produce more mucus, which in turn protects the lining of the gut from the ulcers and inflammation caused by the colitis.