What is helicobacter pylori?
Helicobacter pylori (H. pylori) is a spiral-shaped bacterium found in the stomach, which (along with acid secretion) damages stomach and duodenal tissue, causing inflammation and peptic ulcers. In fact, H. pylori is a leading cause of ulcers among those who develop them. It is believed that H. pylori's shape and characteristics cause the damage that leads to ulcers. Because of their shape and the way they move, the bacteria can penetrate the stomach's protective mucous lining where they produce the enzyme urease, which generates substances that neutralize the stomach's acids. This weakens the stomach's protective mucus, makes the stomach cells more susceptible to the damaging effects of acid and pepsin, and leads to sores or ulcers in the stomach or duodenum (first part of the small intestine). The bacteria can also attach to stomach cells, further weakening the stomach's defensive mechanisms and producing local inflammation. For reasons not completely understood, H. pylori can also stimulate the stomach to produce more acid.
Soon after being infected with H. pylori, most people develop gastritis—an inflammation of the stomach lining. However, most people will never have symptoms or problems related to the infection. When symptoms are present, they may include:
- Abdominal discomfort, which may:
- Be a dull, gnawing pain
- Occur two to three hours after a meal
- Come and go for several days or weeks
- Occur in the middle of the night when stomach is empty
- Be relieved by eating or taking antacid medication
- Weight loss
- Loss of appetite
The symptoms of ulcers may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
Researchers do not yet know what causes certain people to develop H. pylori-related symptoms or ulcers. It is believed that H. pylori is transmitted orally from person to person through close contact (kissing) or through fecal-oral contact. Most people are first exposed to H. pylori during childhood.
How common is it?
Approximately 30 to 40 percent of the U.S. population is thought to have H. pylori, but fortunately, most people don't develop ulcers.
How is it diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for H. pylori may include the following:
- Blood tests: These tests are done to identify antibodies that indicate the presence of the bacterium.
- Stool culture: This is done to check for the presence of abnormal bacteria in the digestive tract that may cause diarrhea and other problems. A small sample of stool is collected and sent to a laboratory by your doctor's office. In two or three days, the test will show whether abnormal bacteria are present
- Breath tests: These tests are done to determine if carbon is present after swallowing a urea capsule—the presence of carbon signals the release of urease by H. pylori.
- Esophagogastroduodenoscopy (also called EGD or upper endoscopy): A procedure that allows the doctor to examine the inside of the esophagus, stomach, and duodenum. A thin, flexible, lighted tube called an endoscope is guided into the mouth and throat, then into the esophagus, stomach, and duodenum. The endoscope allows the doctor to view the inside of this area of the body, as well as to insert instruments through a scope for the removal of a sample of tissue for biopsy (if necessary). Tissue removed during an endoscopy is used to detect the presence of the enzyme urease and examine the bacteria that is present.
Types of treatment
Treatment may include:
- Antibiotics to kill the bacteria
- Medications to suppress acid production, including:
- H2-blockers: These are used to reduce the amount of acid in the stomach by blocking histamine, a powerful stimulant of acid secretion.
- Proton pump inhibitors: These are used to more completely block stomach acid production by stopping the stomach's acid pump—the final step of acid secretion.
- Stomach-lining protectors: These are used to protect the stomach lining from acid and help kill the bacteria.