by MARTYN HALLE, Daily Mail

Researchers have made a major medical breakthrough by developing a vaccine against the crippling digestive illness Crohn's disease.

More than 100,000 people in the UK are stricken by the condition, which causes a chronic inflammation of the intestine.

Professor John Hermon-Taylor of St George's Hospital, London, has developed a vaccine which should be ready within the next five years.

It has already been tested successfully on animals and second-stage trials are to start soon, with human trials in the next three years.

Professor Hermon-Taylor is convinced that a bug - known as MAP (Mycobacterium avium patratuberculosis), found in animals and passed into the food chain - is the cause of most human cases of Crohn's disease.

He was the first doctor to make the link between Crohn's and the bacteria MAP, found in the stomachs of cattle, sheep and pigs and which is thought to be present in as much as 6 per cent of pasteurised milk.

When he tested patients with Crohn's disease for MAP, he found the same bacteria in their intestines as in animals.

However, the Government's Advisory Committee on the Microbiological Safety of Food insists that transmission to humans of MAP from animals is not proven, despite evidence of it getting into the milk supply.

The vaccine would be used to help cure existing sufferers of the illness by stimulating the body's immune system to clear MAP from their bodies.

Three-quarters of people with Crohn's disease require surgery to repair their damaged bowel, and half of those will need a second operation in ten years.

'Around 80 per cent of people I have tested for Crohn's have tested positive for MAP. We believe that the other 20 per cent have a genetic susceptibility to the disease,' says the Professor.

Earlier this year, the Ministry of Agriculture Fisheries And Foods revealed that a national survey of milk had found the bug in 3 per cent of the milk supply.

But it still insists that there is no conclusive link between animal MAP and MAP found in humans. However, companies are heating milk for longer in an attempt to kill the bug. But even this might not be sufficient to give protection, warns Professor Hermon-Taylor.

For more information on Crohn's and MAP, see the Action Research website at www.actionresearch.co.uk or contact the Crohn's Disease Association on 01727 830038.