We need the worms

[RichP714 3,167]

Discovery, 2000,JAN

People who live in developing countries often have parasitic worms in their intestines. On the other hand, they rarely get inflammatory bowel diseases such as ulcerative colitis. Immunoparasitologist Joel Weinstock of the University of Iowa suspected a connection, so he asked six patients with these diseases to quaff a brew of worm eggs. Five of the six went into complete remission within three weeks and stayed symptom‑free for up to five months. The sixth patient, who already had permanent bowel damage, improved significantly.

Animal studies suggest the worms modulate an aspect of the body's immune system called the Thi response, which can mistakenly attack healthy tissue. The worms seem to suppress Thi and enhance the related Th2 response, creating a better environment for them‑and for the host. "For all of our existence these parasites have been with us. They need us, and we need them," Weinstock says. He believes the absence           of the worms in affluent persons' guts could influence diseases such as multiple sclerosis and rheumatoid arthritis.