People with inflammatory bowel disease could soon be swallowing worms in an effort to relieve their symptoms.
The worms don't survive very long in humans
Scientists in the United States have developed a drink containing thousands of pig whipworm eggs.
Trials suggest it can dramatically reduce the abdominal pain, bleeding and diarrhoea associated with the disease.
According to a report in New Scientist, the drink, which is called TSO, could be on sale in Europe by May if it is approved for use by regulators.
A number of studies have suggested that live worms could be an effective treatment for conditions like Crohn's disease and colitis, known collectively as inflammatory bowel disease
In fact, some scientists believe the eradication of worms from human stomachs over the past 50 years may be behind the rise in these conditions.
As the number of infections by parasites, such as roundworms and human whipworms, has fallen, the number of people being diagnosed with inflammatory bowel disease has increased.
In contrast, the condition is still rare in developing countries where parasitic infections remain common.
Scientists at the University of Iowa say they have tested their product on 200 people with the condition. They opted for pig whipworms because they do not survive very long in humans.
They say symptoms disappeared in most of those who took part in the trial. The findings are due to be announced at a conference in the United States in May.
"With our new impressive results, we can come out of the closet," said Dr Joel Weinstock, a gastroenterologist at the University who has developed the treatment.
The product will be made by German company BioCure. It has applied to the European Agency for the Evaluation of Medicinal Products for an EU-wide license to sell the product. Patients would take TSO around twice a month.
Crohn's disease, ulcerative colitis and other forms of inflammatory bowel disease appear to be caused by an overactive immune system, which causes inflammation in the digestive system.
The condition is incurable, and normal treatments include steroids, which can reduce the inflammation, although these have been known to produce side effects.