Helicobacter Pylori

Immunohistochemical staining of H. pylori from a gastric biopsy

Immunohistochemical staining of H. pylori from a gastric biopsy – credit: Wikipedia

This unusual name identifies a specific bacteria that can cause infection of the stomach. This infection can contribute to the development of diseases, such as dyspepsia (heartburn, bloating and nausea), gastritis (inflammation of the stomach), and ulcers in the stomach and duodenum.

The Infection

H. pylori is a fragile bacteria that has found an ideal home in the protective mucous layer of the stomach. These bacteria have long threads protruding from them that attach to the underlying stomach cells. The mucous layer that protects the stomach cells form acid also protects H. pylori. These bacteria do not actually invade the stomach cells as certain other bacteria can. The infection, however, is very real and it does cause the body to react. Infection-fighting white blood cells move into the area, and the body even develops H. pylori antibodies in the blood.

H. pylori infection probably occurs when an individual swallows the bacteria in food, fluid, or perhaps from contaminated utensils. The infection is likely one of the most common worldwide. In many cases it does not produce symptoms. In other words, the infection can occur without the person knowing it. The infection remains localized to the gastric area, and probably persists unless specific treatment is given.

How is H. pylori Infection diagnosed?

There are currently four ways to diagnose H. pylori infection. During endoscopy (a visual exam of the stomach through a thin, lighted, flexible tube), the physician can remove small bits of tissue through the tube. The tissue is then tested for the bacteria. A breath test is also available. In the test, a substance called urea is given by mouth. A strong enzyme in the bacteria breaks down the urea into carbon dioxide, which is then exhaled and can be measured, and finally, there is a blood that measures the protein antibodies against these bacteria that are are present in the blood. This antibody can mean the infection is present, or that is was present in the past and is now cleared. In other words, a person can have a positive blood test but no infection. Finally, there is a stool test that measures a protein that is shed by the bacteria.

Stomach Cancer and Lymphoma

These two types of cancer are now known to be related to H. pylori bacteria. This does not mean that all people with H. pylori infection will develop cancer; in fact, very few do. However, it is likely that if the infection is present for a long time, perhaps from childhood, these cancers may then develop. This is another reason why it is important to treat H. pylori infection.


H. pylori is a very common infection of the stomach. It may be the most common infection in the world. It is now clear that the infection is directly related to the development of stomach and duodenal ulcers, and it is likely that it may be related of cancers involving the stomach. There are several diagnostic tests available, and effective treatment can prevent the recurrence of ulcers and perhaps the development of cancer.