Monday, June 30, 2008

I Think I'll Go Eat Worms

A gastroenterologist from the University of Iowa, Joel Weinstock, has been conducting human studies that involve feeding worms to people . The people have Crohn's disease, a bowel disorder, and the worms are Trichuris suis eggs, a parasite found in pigs. Of 29 Crohn's patients, 23 felt relief, and 21 went into complete remission. A second study showed that eating the parasite eggs also improved ulcerative colitis. Weinstock's reasoning here was that human beings evolved in tandem with parasites (also bacteria and viruses) and when modern hygiene eliminates them, we get sick. He formulated his theory after noticing a sharp upturn in inflammatory bowel disease about ten years after modern hygiene arrives at some new corner of the Third World.

All this was reported in an article in yesterday's New York Times, but it's not the first time I've read something similar. Too much cleanliness has been implicated in upswings in asthma, for instance. Our immune systems apparently need something familiar to work on -- parasites, dust, allergens -- and if you eliminate too many of these, the immune system gets cranky and misbehaves. We need a certain amount of filth.

I'm tempted to make a metaphor here. We also evolved with bloody competition and violence. I would say that the evolutionary advantages of violence would make a good novel, except that I already wrote that book (An Alien Light) twenty years ago. Too bad -- I need a novel topic now and I don't have one.

Maybe beneficial parasites...

10 comments:

Leigh Anna said...
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Leigh Anna said...

Microbes are sorely misunderstood.

There are lots of beneficial microbes, or the factoid I love to gross out kids with: one third of your fecal matter by weight is bacteria. But our soil, our digestive systems, some of our foods, etc. all depend on them. When we finally venture out in huge spaceships for generations at a time, there will have to be carefully introduced microbes on board for various functions. It is the only way to have a sustaining ecosystem. There will be a staff microbiologist.

But discussing disease (since that is what most people think about when you mention germs), from an overall population standpoint even the worst epidemic allows the population to survive. There are always people who recover or who have a natural immunity. Diseases also get milder as they go along.

So it is probably horrible to think of it this way, but microbes are our natural predators and serve as population control the same way areas where we've killed off all the wolves, the deer population goes up until the land can't support them. Microbes aren't bad anymore than the wolves are. But the deer probably think they are.

Microbes are a constant reminder that no matter how much we bunker ourselves into concrete and glass and cleaning solutions, we are still part of the natural world on this planet.

Besides, have you ever looked at syphilis under a microscope? It's latin name means a pale turning thread and that is how it looks. A pale corkscrew. Bacteria and viruses are elegant, resourceful, and diverse. We can't live without them and they have shaped us and our society. (Plagues and Peoples and Epidemics and Ideas)

99.9% of bacteria are harmless or helpful to humans. That .1%, however, may have their uses in the grand scheme of things too. So in your discussion of beneficial parasites, define beneficial and beneficial to whom?

bluesman miike Lindner said...

Interesting! I read about that study in the February issue of the INFLAMMATORY BOWEL DISEASE ILLUSTRATED journal. (Kidding!) But I wonder what a double-blind placebo experiment might show.

Nancy Kress said...

It was a double-blind experiment with placebos.

Mike said...

I tend to agree about our immune systems needing something to fight against. I have no data to back it up, but it seems food allergies are more prevalent. Of course, that could be do to better understanding of our bodies and how they work.

kendall said...

Some things are also better-diagnosed, more closely tracked, etc. than they used to be.

On the other paw, I suppose some things might always be inconsistently or under diagnored/reported.

Sometimes I think we're comparing apples to oranges when looking at how frequent some things are, over time; we can't really control for variations in awareness, diagnosis, reporting, etc., can we?

bluesman miike Lindner said...

An ah-deer for a novel, Nancy? Hmmm...let's see...how about a woman falling in love with an Artificial Intelligence?

gdtownshende said...

I know someone with Crohn's Disease, but I don't think she'd be so keen on eating some worms.

Neal Holtschulte said...

Sports, I think, are an adequate replacement for the human evolutionary need for "bloody competition and violence". So the question is: sports is to violence as _____ is to disease?

Bill Dunning said...

I remember hearing about this. I think Carl Zimmer covered it in his book Parasite Rex (wonderful book).

Also, I read An Alien Light just a few weeks ago (wonderful book).