Gut problems? Try the worm diet
2004-12-14 14:53
Paris - The parasite known as Trichuris suis has been given the okay in an unconventional experiment to tackle inflammatory bowel disease (IBD), an ailment that is on the rise in Western countries.
Twenty-nine people with a mild form of Crohn's disease, a potentially disabling IBD, were asked to swallow 2 500 worm eggs every three weeks for six months. The eggs were mixed up in a soft drink to disguise the taste.
Four patients withdrew before the halfway mark, and a fifth stopped taking the worms when she became pregnant.
Of the 24 who stayed in the experiment, 22 experienced a major improvement in their health after three months, and 19 of them had no symptoms at all.
By the end of the experiment, the tallies had risen to 23 out of 24 for improvement. Twenty-one of the 23 were symptom-free.
None of the volunteers reported any worsening of their symptoms, and there were no side effects.
Crohn's disease
Crohn's disease typically features cramping abdominal pain, bleeding and diarrhoea among its symptoms, which are often combated by steroids or antibiotics.
The University of Iowa researchers note that the rise in IBD over the past 50 years in rich countries has coincided with a plunge in infections by classic intestinal parasites such as roundworm and human whipworms, driven out by better hygiene.
In developing countries, though, these parasites are common but IBD is very rare.
Their theory is that the eradication of human intestinal parasites over such a short period is a new and potentially traumatic event in evolutionary terms.
Our immune systems developed over millions of years to cope with the presence of such parasites and without them our bowels can become overactive.
The porcine parasite seems to be in a class of its own because it restores normal gut response, but there is no evidence that it can colonise humans.
Once in the bowel, the egg hatches into the worm. Because the worm has a short life cycle, its chances of adapting and spreading to other parts of the body are minimal, they believe.
The worm eggs are shed in stools, but they cannot colonise another host unless they have been incubated in soil for several weeks - a risk that is unlikely in developed countries where IBD is a problem.
Human whipworms 'different'
Human whipworms, however, are a different proposition. Half a billion people carry this parasite, which can cause problems such as anaemia.
The study appears on Tuesday in Gut, published by the British Medical Association (BMA).
It was authorised after one of the researchers, gastroenterologist Joel Weinstock, carried out preliminary tests on volunteers with Crohn's and another IBD called ulcerative colitis.
That research was so convincing that a Germany company called BioCure (whose sister company, BioMonde, sells leeches and maggots for treating wounds) leapt into the pig whipworm business.
It has devised a drinkable mix of eggs under the name of "TSO" (for Trichuris Suis Ova) - presumably because DPW ("Drinkable Pig Whipworms") may not be a smart branding strategy.