The bacteria your doctor is referring to is Helicobacter pylori – a small bacteria that lives in the stomach. It is estimated that over 50% of the world’s population is colonized with the bacteria and although over 75% of them are asymptomatic, H. pylori is a known cause of gastric and duodenal ulcers as well as stomach cancer.
The mechanism behind H. pylori’s disease process is its propensity to cause inflammation of the stomach lining (gastritis). This inflammation weakens the stomach and small intestine’s mucous barrier which acts as a defense against acid corrosion. Therefore, stomach and duodenal ulcers occur at areas where there are high concentrations of H. pylori.