Parasites as friends

How the parasitic worm has turned

I've mentioned before the apparent benefits of having a good dose of intestinal worms for your immune system. The story has been turning up in various forms for a few years now, but it's apparently discussed recently in a Science article:

Professor Roberts, whose work is published in Science, explains: "It is like a three-legged stool - the microbes, worms and immune system regulate each other.

"The worms have been with us throughout our evolution and their presence, along with bacteria, in the ecosystem of the gut is important in the development of a functional immune system."

Professor Grencis adds: "If you look at the incidence of parasitic worm infection and compare it to the incidence of auto-immune disease and allergy, where the body's immune system over-reacts and causes damage, they have little overlap. Clean places in the West, where parasites are eradicated, see problems caused by overactive immune systems. In the developing world, there is more parasitic worm infection but less auto-immune and allergic problems.

"We are not suggesting that people deliberately infect themselves with parasitic worms but we are saying that these larger pathogens make things that help our immune system. We have evolved with both the bugs and the worms and there are consequences of that interaction, so they are important to the development of our immune system."

I don't know: it seems he is suggesting that catching them is a good idea. Here's more:

Intestinal roundworm parasites are one of the most common types of infection worldwide, although in humans increased hygiene has reduced infection in many countries. High level infections by these parasites can cause disease, but the natural situation is the presence of relatively low levels of infection. The team's work suggests that in addition to bacterial microflora, the natural state of affairs of our intestines may well be the presence of larger organisms, the parasitic roundworms, and that complex and subtle interactions between these different types of organism have evolved to provide an efficient and beneficial ecosystem for all concerned.

There's no mention of how you might get the benefits of a gut full of worms without actually having a gut full of worms, but I am sure someone must be thinking about it.