What causes H pylori infection?

H pylori is a bacterium that is present in the stomach and does not cause any symptoms.

H pylori infection is caused most commonly by consuming food or water or any liquid contaminated with the fecal matter containing the H pylori bacteria. It can be transmitted through direct contact with the saliva or vomit of the infected person. It is still unclear why some people with H pylori develop the symptoms while others do not.

Some people with H pylori infection develop a variety of digestive problems, such as persistent inflammation of the stomach (chronic gastritis), or inflammation of the duodenum (duodenitis), which can transform into complications, such as stomach ulcers and cancer.

The changes in stomach cell lining leading to inflammation and cancer occur in the following steps:

• The bacteria infects the protective tissue (mucosa) that lines the stomach.
• Certain enzymes and toxins are released.
• The immune system gets activated.
• Together, these factors may injure the cells of the digestive tract (stomach or duodenum) that result in digestive system disorders.
• The development of stomach cancer is a multistep process progressing from chronic gastritis, degeneration or shrinkage of gastric glands (glandular atrophy), replacement of gastric cell lining with intestinal cell lining (intestinal metaplasia) to the stage of development of abnormal cells in the stomach tissue (dysplasia), proceeding to a stage of cancer.

Who is at risk for H pylori infection?

In developing countries, you have greater chances of getting an H pylori infection during your childhood. However, in the United States and other developed countries, H pylori infections are more common during adult age.

You are at risk of H pylori infection if you:

• Live in a crowded house
• Live in places without a reliable supply of clean water
• Live in a developing country (lack of sanitation, lower socioeconomic status, unfiltered water)
• Live with someone who has an H pylori infection
• Eat restaurant food
• Smoke
• Have a family history of peptic ulcer

Consumption of chili peppers and concurrent parasite infestation is protective against H pylori.

Which tests are used to diagnose H pylori infection?

The most common tests used to diagnose H pylori are:

• Urea breath tests: After you drink a specialized solution, you are then asked to blow through a straw into a glass tube. Your breath will then be tested for the presence of carbon molecules, which make the test positive (H pylori infection is present).
• Stool tests: Stool antigen tests detect H pylori proteins in the stool.
• Blood tests: Specific antibody tests done using the blood can help detect active or old infection.

How is H pylori infection treated?

Successful treatment of H pylori can help the ulcer heal, prevent recurrence of ulcers, and reduce the risk of ulcer complications (such as bleeding and cancer).

The most effective treatment for H pylori involves medications to be taken for two weeks and is called triple therapy, which includes the following:

1. Proton pump inhibitor, such as omeprazole, pantoprazole, Prevacid (lansoprazole), and rabeprazole
2. Bismuth subsalicylate
3. Two different antibiotics (metronidazole and tetracycline or metronidazole and amoxicillin)

The best treatment regimens may vary with your antibiotic resistance.

It is important to take the entire course of all medications to get maximum results from H pylori treatment.

After completing H pylori treatment, repeat testing is usually performed to ensure that the bacterium has been eradicated. This is typically done with a breath or stool test on follow-up. 

Blood tests are not recommended on follow-ups. The antibody detected by the blood test often remains in the blood for four or more months after treatment even after the bacterium has been eliminated.