The prevalence of inflammatory bowel disease (IBD) in North America, the main forms of which are Crohn’s Disease and Ulcerative Colitis, has increased markedly over the last half-century. Two generations ago the incidence of IBD was 1 in 10,000, and now it’s 1 in 250. Nobody is quite sure what causes IBD; it seems to fall into that diffuse category of autoimmune disorders which are characterized by the body’s defenses attacking some aspect of itself. Researchers suggest environment, diet and genetics may all be involved.

Joel V. Weinstock M.D., a Professor of Medicine at Tufts, is a gastroenterologist whose special expertise is in parasitic worm infestations. Dr Weinstock looked at the epidemic and thought it unlikely that genetics were the reason for the enormous increase, because it occurred so quickly. He also knew that over the last 50 years, big changes have occurred in the environment of the bowel. We have virtually eliminated parasitic worms from the GI tract through improved hygiene, de-worming efforts, and lots of new drugs that sterilize the bowel.

Parasitic intestinal worms do not induce bowel inflammation (which is the typical response to any invasion); instead, they seem to bolster the host’s anti-inflammatory response and create a peaceful environment that doesn’t reject them. Dr. Weinstock theorized that when the worms were evicted from our bodies the immune system went out of kilter. Hygiene may have made our lives better; however, in the process of eliminating exposure to the things that can make us sick, we’ve also eliminated exposure to things that keep us well. If, after long co-evolution, the human immune system came to depend on the worms for proper functioning, then perhaps reintroducing benign worms to patients with IBD might bolster their immune response.

Pig farmers are chronically exposed to Tricuris suis, the pig whip worm which causes no problems in humans. So Dr. Weinstock gave T. suis eggs to 29 patients with Crohn’s disease at three-week intervals for 24 weeks; 23 of them went into complete remission. He repeated the study with chronic ulcerative colitis patients, and half of them improved significantly.

Now researchers all over the world are using T. suis eggs on patients with a host of autoimmune diseases including Multiple Sclerosis, hay fever, asthma, and food allergies, all of which have also exploded over the last 50 years.

This is a metaphor for life: we are part of our environment and not separate from it. We participate in an interactive community that includes bacteria, fungi, viruses, and even a few parasites — all important participants in keeping us healthy. When we change our ecosystem and disturb any of its key players our systems can get out of whack. The relentless pursuit of hygiene and drugs for every symptom are actually weakening us.

I’m going to eat some worms.