Helicobacter pylori is a variety of bacteria that can cause severe infections and diseases if present in the stomach. The bacteria is notable in that it took over 100 years from its discovery to be associated with the illnesses it can cause. Ulcers, gastritis, and some stomach and intestinal cancers can all be caused by Helicobacter pylori infections.
In 1875, German scientists G. Bottcher and M. Letulle suggested that ulcers could be caused by bacteria. They couldn’t prove their theory, due to the inability to culture the bacteria they thought responsible, and their results were largely ignored by the scientific community. About 20 years later, additional support was found by Italian researchers after discovering a helix-shaped bacteria growing in the stomach of dogs. Yet not until nearly a century later was the theory fully researched and developed.
Two Australian scientists, Robin Warren and Barry Marshall, began extensive research on the bacteria in 1981. Unlike in the original research by Bottcher and Letulle, Warren and Marshall were successfully able to culture the bacteria for study. The methods of the Australian team were radical, including an experiment where Marshall ingested samples of the bacteria to see if it would induce stomach problems. The experiment was successful, and Marshall and Warren were able to prove that the bacteria was also treatable with antibiotics.
Helicobacter pylori can often be identified through blood or breath testing. An endoscopy may also be performed to confirm findings. In this procedure, a small tube is inserted down the throat and into the stomach, where samples of material are obtained. Once the presence of the bacteria is confirmed, a doctor can choose which antibiotic treatment best suits the patients needs.
The bacteria is considered a cause of many diseases. Peptic and gastric ulcers are often a result of a Helicobacter pylori infection. Chronic dyspepsia that is not a result of ulcers may also be caused by the bacteria. Some studies suggest that 70-90% of stomach cancers are caused by Helicobacter pylori infections. Despite these frightening illnesses, many people who have the bacteria in their stomach have no symptoms and may not encounter any problems.
Helicobacter pylori enters the system in a variety of ways. It is a contagious bacteria that can be found in contaminated food or water. Some studies also suggest that it can be passed through oral contact, such as kissing, from an infected person to a non-infected person. Maintaining a clean and hygienic environment can help avoid contamination. Some estimates suggest that about 4 billion people, or two-thirds of the population, are infected with the bacteria.
If you experience frequent stomach pain, heartburn, or consistent vomiting, experts recommend that you contact a doctor regarding testing for Helicobacter pylori. Although the vast majority of those who have the bacteria are asymptomatic, unusual stomach-related symptoms should be treated with caution. Many strains of the bacteria are treatable with antibiotics, which can stop the infection before it has a chance to cause additional problems.
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
People with a history of peptic ulcer disease, active gastric ulcer, or active duodenal ulcer associated with H. pylori infection should be treated. Successful treatment of H. pylori can help the ulcer to heal, prevent ulcers from coming back, and reduce the risk of ulcer complications (like bleeding).
Medications — No single drug cures Helicobacter pylori infection. Treatment involves taking several medications for 7 to 14 days.
Most of the treatment regimens include a medication called a proton pump inhibitor. This medication decreases the stomach's production of acid, which allows the tissues damaged by the infection to heal. Examples of proton pump inhibitors include lansoprazole, omeprazole, pantoprazole, rabeprazole, dexlansoprazole, and esomeprazole.
Two antibiotics are also generally recommended; this reduces the risk of treatment failure and antibiotic resistance.
Although the optimal H. pylori treatment regimen continues to be investigated, the American College of Gastroenterology has recommended four specific drug regimens that use a combination of at least three medications. These regimens successfully cure infection in up to 90 percent of people. For the H. pylori treatment to be effective, it is important to take the entire course of all medications.
Side effects — Up to 50 percent of patients have side effects while taking H. pylori treatment. Side effects are usually mild, and fewer than 10 percent of patients stop treatment because of side effects. For those who do experience side effects, it may be possible to make adjustments in the dose or timing of medication. Many of the regimens cause diarrhea and stomach cramps.
Treatment failure — Up to 20 percent of patients with Helicobacter pylori infection are not cured after completing their first course of treatment. A second treatment regimen is usually recommended in this case. Retreatment usually requires that the patient take 14 days of a proton pump inhibitor and two antibiotics. At least one of the antibiotics is different from those used in the first treatment course.
Follow-up — After completing H. pylori treatment, repeat testing is usually performed to ensure that the infection has resolved. This is typically done with a breath or stool test. Blood tests are not recommended for follow up testing; the antibody detected by the blood test often remains in the blood for four or more months after treatment, even after the infection is eliminated.
There is a general consensus among doctors that patients should be treated if they are infected with H. pylori and have ulcers. The goal of treatment is to eradicate the bacterium, heal the ulcers, and prevent the ulcers' return. Patients with MALT lymphoma of the stomach also should be treated. MALT lymphoma is rare, but the tumor often quickly regresses upon successful eradication of H. pylori.
There currently is no formal recommendation to treat patients infected with H. pylori without ulcer disease or MALT lymphoma. Since antibiotic combinations can have side effects and stomach cancers are infrequent in the United States, it is felt that the risks of treatment to eradicate H. pylori in patients without symptoms or ulcers may not justify the unproven benefits of treatment for the purpose of preventing stomach cancer. On the other hand, H pylori infection is known to cause atrophic gastritis (chronic inflammation of the stomach leading to atrophy of the inner lining of the stomach). Some physicians believe that atrophic gastritis can lead to cell changes (intestinal metaplasia) that can be precursors to stomach cancer. Studies have also shown that eradication of H pylori can reverse atrophic gastritis. Thus, some doctors are recommending treatment of ulcer- and symptom-free patients infected with H. pylori.
Many physicians believe that dyspepsia may be associated with infection with H. pylori. Although it is not clear if H. pylori causes the dyspepsia, many physicians will test patients with dyspepsia for infection with H. pylori and treat them if infection is present.
Scientists studying the genetics of H. pylori have found different strains (types) of the bacterium. Some strains of H. pylori appear to be more prone to cause ulcers and stomach cancer. Further research in this area may help doctors to intelligently select those patients who need treatment. Vaccination against H. pylori is unlikely to be available in the near future.