This unusual name identifies a specific bacterium 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. Rarely, it can lead to stomach cancer. It will be useful to know some things about the upper digestive tract to understand how and where Helicobacter pylori infection can occur.
When food is swallowed, it passes through the esophagus (the tube that connects the throat to the stomach). It then enters the larger upper part of the stomach. A strong acid that helps to break down the food is secreted in the stomach. The narrower, lower part of the stomach is called the antrum. The antrum contracts frequently and vigorously, grinding up the food and squirting it into the small intestine. The duodenum is the first part of the small intestine, just beyond the stomach. The stomach, including the antrum, is covered by a layer of mucous that protects it from the strong stomach acid.
It is known that alcohol, aspirin, and arthritis drugs such as ibuprofen can disrupt the protective mucous layer. This allows the strong stomach acid to injure underlying stomach cells. In some people, corticosteroids, smoking, and stress appear to contribute in some way. Until the mid-1980s, it was felt that one or more of these factors working together led to the development of gastritis and ulcers. Since that time, scientific research has confirmed that Helicobacter pylori (H. pylori) has a major role in causing these diseases. Compelling research now supports Helicobacter pylori as a cause of many ulcers and gastritis.
The Infection
H. pylori is a fragile bacterium 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 from 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. The rate of infection increases with age, so it is found more often in older people. It also occurs frequently in young people in the developing countries of the world, since the infection tends to be more common where sanitation is poor or living quarters are cramped. 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 stomach, and often 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 this 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. There is also a blood test that measures the protein antibodies against these bacteria that are present in the blood. This antibody can mean the infection is present, or that it was present in the past and is now cleared. In other words, a person can have a positive antibody blood test but no infection. Finally, there is a stool test that measures a protein that is shed by the bacteria.
Gastritis and Dyspepsia
H. pylori symptoms can include abdominal discomfort, bloating, nausea and perhaps vomiting. These symptoms, however, are not specific to H. pylori. For example, the person may also have symptoms that suggest ulcers — burning or pain in the upper abdomen, usually occurring about an hour or so after meals or even during the night. The symptoms may be relieved temporarily by antacids, milk, or medications that reduce stomach acidity. Yet, the physician does not find an ulcer when the patient is tested by x-ray or endoscopy. When H. pylori is found in the stomach, it is tempting to believe that it is the cause of the symptoms, although this connection is not always clear cut. The physician will usually prescribe antibiotic therapy to see if clearing the infection relieves symptoms.
Ulcers
Stomach Ulcers
H. pylori infection is found in 60 to 80 percent of the those with stomach ulcers. H. pylori most likely weakens the protective mucous layer of the stomach. This allows acid to seep in and injure the underlying stomach cells. However, there is still a great deal of research to be done to unravel this relationship. For example, only about 20% of patients infected with H. pylori will develop ulcers.
Duodenal ulcers
In times past, physicians were taught “no acid, no ulcer.” The medical profession felt the single most important factor causing duodenal ulcers to form was strong stomach acid. Research has now shown that about 70% to 80% of all patients who develop duodenal ulcers have H. pylori infection in the stomach as well. Medical studies are under way to determine the relationship between the two and how an infection in the stomach can be related to a duodenal ulcer. Acid is still important; patients without acid in the stomach do not develop duodenal ulcers. However, physicians now accept the fact that the infection is directly related to the development of duodenal ulcers. It is now rather easy to clear duodenal ulcers with the strong acid-reducing medicines available. But, the ulcers will usually recur unless the H. pylori infection is also cleared from the stomach.
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.
When is Treatment Necessary?
Those found to be infected with H pylori should be offered treatment. There is some debate whether to treat patients found to have H pylori infection but no symptoms but those with ulcers, cancer or symptoms of gastritis should be treated. The treatment consists of a series of antibiotics combined with antacid medications. H. pylori is buried deep in the stomach mucous, so it is difficult to get rid of this infection. Several antibiotic drugs are always used together to prevent the bacteria from developing resistance to any one of them. There are, however, emerging strains of H pylori that are resistant to one or more antibiotics historically used to treat the infection. The likelihood of infection may vary depending on where a patient lives. It is best to work with your physician to find the most effective regimen.
After completion of treatment, it is advised to confirm clearance of the infection.
Summary
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 often related to 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.