Definition of Helicobacter pylori :

Helicobacter pylori (H. pylori) is the bacteria responsible for most ulcers and many cases of stomach inflammation (chronic gastritis).

The bacteria can weaken the protective coating of the stomach, allowing digestive juices to irritate the sensitive stomach lining.

Causes, incidence, and risk factors:

As many as half of the world's population is infected with H. pylori. Those living in developing countries or crowded, unsanitary conditions are most likely to contract the bacterium, which is passed from person to person. H. pylori only grows in the stomach, and is usually contracted during childhood.

Interestingly, many people have this organism in their stomach, but don't get an ulcer or gastritis. It seems that other factors must also be present for the damage to take place. The factors that increase your risk for an ulcer from H. pylori include:

• Abnormal immune response in your stomach
• Certain lifestyle habits, like coffee drinking, smoking, and alcohol consumption