Breath test spots toxic bug

A simple breath test should be enough to detect infection from a bacterium that is thought to cause severe indigestion, stomach ulcers and cancer, say doctors.

At present, doctors often use an endoscope to look for the presence of Helicobacter pylori in the digestive tract.

This involves feeding a tube with a camera on the end down the patient's throat and into the stomach. It can be uncomfortable and distressing.

A study published in the British Medical Association has found that a breath test is every bit as effective at diagnosing H. pylori infection.

Researchers examined 708 patients with indigestion who had been referred to hospital for endoscopic investigation to ascertain whether they were infected with H pylori, and had either a stomach ulcer, or signs of stomach cancer.

A total of 356 patients received a non-invasive breath test for H pylori and 352 received endoscopy plus H pylori testing.

After 12 months, the breath test was found to be as effective and safe as endoscopy.

Not only did patients prefer it, it was also cheaper.

Radioactive test

Professor Kenneth McColl, of Western Infirmary, Glasgow, told BBC News Online that his research suggested that people under the age of 55 who showed no symptoms of stomach cancer did not require endoscopy.

He said that people who were found to have H. pylori infection were given medication to treat stomach ulcers as standard practice, whether they had an ulcer or not.

The breath test works by giving patients a drink of radioactive urea.

In the presence of H. pylori this is broken down to radioactive carbon dioxide, which can be detected in the breath.

Professor McColl said: "It was thought that patients required endoscopy to reassure them, but our study found that this was not the case.

"Most expressed a preference for the less invasive breath test."

"It was thought that patients required endoscopy to reassure them, but our study found that this was not the case"

Professor Kenneth McColl

Toxin

H pylori causes problems because it injects a toxin into cells in the stomach lining.

This causes internal structures in the cells to swell up, and spill chemicals called enzymes out.

These help break down stomach mucus, and makes the whole layer of lining cells "leaky", allowing bacteria to obtain nutrients.

H pylori is blamed for an estimated 19 out of 20 duodenal ulcers, and the majority of gastric ulcers.