have shown that people with the bug are about four or five times more likely to develop stomach cancer. Researchers hope that by treating the bacterium they can cut the risk of stomach cancer. The scientists will recruit about 56,000 people into the five-year trial that will be conducted throughout Britain. Blood samples from half the group will be screened and if they test positive for the bacteria they will be given antibiotics. Blood from the other half will not be screened and will act as a control group. After 15 years both groups will be followed up to see if they develop cancer.