Digestive Disorders Health Center

H. pylori (Helicobacter pylori)

Stress, spicy foods, type A personality. Which of these causes most stomach ulcers? The answer: none of them. Research shows that most ulcers -- 80% of stomach ulcers and 90% of those in the duodenum, the upper end of the small intestine -- develop because of infection with Helicobacter pylori (H. pylori).

How H. pylori Makes You Sick

H. pylori is a spiral-shaped bacterium commonly found in the stomach. The bacteria's shape and the way they move allow them to penetrate the stomach's protective mucous lining, where they produce substances that weaken the lining and make the stomach more susceptible to damage from gastric acids.

The bacteria can also attach to cells of the stomach, causing stomach inflammation (gastritis), and can stimulate the production of excess stomach acid. Over time, infection with the bacteria can also increase the risk of stomach cancer.

Although it is not known how H. pylori infection is spread, scientists believe it may be contracted through food and water. According to the National Institutes of Health, approximately 20% of people under 40 years old and half of adults over 60 years old in the U.S. are infected, with higher rates in developing counrtries.

Symptoms of H. Pylori

Having H. pylori infection doesn't necessarily mean you'll have ulcers or develop stomach cancer. In fact, most people infected with the bacteria never have symptoms or problems such as ulcers. Only a small number of people with the infection develop stomach cancer. It's not clear why some infected people develop ulcers and others don't.

When H. pylori does cause symptoms, they are usually either symptoms of gastritis or peptic ulcer disease. The most common symptom of peptic ulcer disease is gnawing or burning abdominal pain, usually in the area just beneath the ribs. This pain typically gets worse when your stomach is empty and improves when you eat food, drink milk, or take an antacid.

Other symptoms may include:

• Weight loss
• Loss of appetite
• Bloating
• Burping
• Nausea
• Vomiting (vomit may be bloody or look like coffee grounds)
• Black, tarry stools

How H. pylori Is Diagnosed

Several types of tests are available to help diagnose H. pylori infection and/or ulcers. These include:

Upper GI(gastrointestinal) series. An X-ray of the upper GI tract -- the esophagus, stomach, and duodenum. Prior to the X-ray you must swallow a chalky liquid called barium, which makes ulcers show up on the X-ray.

Endoscopy. A procedure that involves snaking a thin, flexible tube with a camera down the esophagus, through the stomach, and into the small intestine to view the upper GI tract.

Blood test. A test that looks for antibodies in the blood that indicate exposure to H. pylori.

Stool test. A test that uses a small sample of stool to look for evidence of infection.

Urea breath test. A test used to check for the presence of a gas produced by the bacteria.