Helicobacter Pylori

Helicobacter pylori (H. pylori) is a spiral shaped bacterium that lives in or on the lining of the stomach. It causes more than 90 percent of ulcers, which are sores in the lining of the stomach or the duodenum (the first part of the small intestine). Before 1982, when this bacterium was discovered, spicy food, acid, stress and lifestyle were considered the major causes of ulcers. Since it is now known that most ulcers are caused by an infection with H. pylori, they can be cured with appropriate antibiotics.

About two-thirds of the world's population is infected with H. pylori. In the United States, H. pylori is found more often in older adults, African Americans, Hispanics and lower socioeconomic groups.

Most persons who are infected with H. pylori never have any symptoms or problems related to this infection; however, H. pylori can cause gastritis (inflammation of the lining of the stomach) or ulcers of the stomach or duodenum. About 25 million Americans suffer from ulcers.

The most common ulcer symptom is gnawing or burning pain in the abdomen between the breastbone and the navel. Commonly, the pain occurs when the stomach is empty — between meals and in the early morning hours — but it also can occur at other times of the day. It may last from minutes to hours and may be relieved by eating or taking antacids. Less common symptoms include nausea, vomiting and loss of appetite. Sometimes ulcers may bleed; if bleeding continues for a long time, it may lead to anemia with weakness and fatigue. If bleeding is heavy, blood may appear in vomit or stool. Stool containing blood may appear tarry or black.

Physicians have several methods to test for H. pylori infection. Blood tests can determine if a person has been infected by measuring specific H. pylori antibodies. A breath test can determine if H. pylori is in the patient's stomach. In this test, the patient is given a harmless substance — urea with carbon — to drink. H. pylori breaks down this urea, and the carbon is absorbed into the bloodstream and lungs and then exhaled in the breath. By collecting this breath, the health care provider can measure the carbon and determine whether the bacteria are present.

A physician also can perform endoscopy, in which a small flexible instrument with a camera inside is inserted through the mouth into the esophagus, stomach and duodenum to look for ulcers. During endoscopy, biopsy specimens (tissue samples) of the stomach lining can be obtained. Several tests can be performed on these tissue samples to determine if the patient is infected with H. pylori.

Persons with stomach or duodenal ulcers should be tested for H. pylori and, if found to be infected, be treated with an antibiotic. Antibiotics are the new cure for ulcers; therapy consists of one to two weeks of one or two antibiotics and a medicine that will reduce the acid in the stomach. This treatment is a dramatic medical advance because eliminating H. pylori with antibiotics means that there is a greater than 90 percent chance the ulcer can be cured for good.

It is not known how the bacteria get into the body or why some people with H. pylori become ill while others do not. The bacteria most likely spread from person to person through the fecal-oral route (when infected fecal matter comes in contact with hands, food or water) or the oral-oral route (when infected saliva or vomit comes in contact with hands, food or water).

Since the source of H. pylori is not yet known, recommendations for avoiding infection have not been made. In general, it is always wise to eat food that has been properly prepared and to drink water from a source that is known to be clean and safe.

Recent studies have shown an association between long-term infection with H. pyloriand the development of gastric (stomach) cancer. Gastric cancer is the second most common cancer worldwide; it is most common in countries such as Colombia and China, where H. pylori infects more than half the population in early childhood. In the United States, where H. pylori is less common in young people, gastric cancer rates have decreased since the 1930s.

Consult your physician if you are concerned about H. pylori. Although knowledge about the bacteria is incomplete, scientists are working to find out how persons become infected, why some people develop symptoms and what the best treatments are.

(This HealthBeat was adapted from a fact sheet developed by the U.S. Centers for Disease Control and Prevention.)