H. pylori Infection (Helicobacter pylori)

Overview

Helicobacter pylori, usually shortened to H. pylori, is a spiral-shaped bacterium that lives in the lining of the stomach. It is one of the most common chronic infections in the world, and many people carry it for years without ever feeling unwell. The bacterium is able to survive the stomach's harsh acid by burrowing into the protective mucous layer.

In some people, H. pylori inflames and weakens the stomach lining, leading to gastritis and peptic ulcers. Long-standing infection is also a known risk factor for stomach cancer. Because the infection can be cured with a short course of medication, finding and treating it is an important part of managing ulcers and certain other stomach problems.

Symptoms

Most people with H. pylori have no symptoms at all. When the infection causes inflammation or an ulcer, symptoms may include:

• A dull or burning pain in the upper abdomen, often worse when the stomach is empty
• Bloating, frequent belching, or a feeling of fullness
• Nausea or loss of appetite
• Unintended weight loss

Warning signs of a complication such as a bleeding ulcer include vomiting blood or material that looks like coffee grounds, and black, tarry stools. These require emergency care.

Causes

H. pylori is caused by the bacterium itself, which spreads from person to person and through contaminated food or water. The exact way it passes is not fully understood, but it likely travels through saliva, vomit, or stool, often within households and during childhood.

Once it reaches the stomach, the bacterium settles in the mucous lining and can trigger ongoing, low-grade inflammation. Why some infected people develop ulcers or cancer while others never have problems depends on the strain of bacteria, the person's genetics, and other factors such as smoking and NSAID use.

Risk Factors

• Living in crowded conditions or with many family members
• Lack of reliable clean water
• Living in or coming from a region where the infection is widespread
• Living with someone who has H. pylori
• Infection often acquired in childhood

Diagnosis

Several reliable tests can detect H. pylori. Many do not require any invasive procedure:

• Urea breath test: You drink a special solution and a breath sample shows whether the bacterium is present.
• Stool antigen test: Detects bacterial proteins in a stool sample.
• Blood test: Detects antibodies, but cannot tell a current from a past infection, so it is used less often.
• Upper endoscopy with biopsy: A camera examines the stomach and a tissue sample is tested, used when an ulcer or other problem also needs to be looked at directly.

Certain medications, including acid reducers and antibiotics, can affect test results, so timing of the test matters.

Treatment

H. pylori is treated with a combination of medications, usually taken together for one to two weeks.

• Antibiotics: Two different antibiotics are used together to clear the bacterium and reduce resistance.
• Proton pump inhibitor (PPI): An acid-reducing medicine such as omeprazole helps the antibiotics work and allows the stomach lining to heal.
• Bismuth: Sometimes added to the regimen to improve cure rates.

Finishing the full course exactly as prescribed is important to clear the infection. A follow-up breath or stool test is often done weeks later to confirm the bacterium is gone, especially after an ulcer.

Prevention

• Wash hands thoroughly with soap and water, especially after using the bathroom and before eating
• Drink clean, safe water
• Eat food that has been properly washed and cooked
• Complete the full course of treatment if you are infected, and confirm clearance afterward

When to See a Doctor

See a doctor for ongoing upper abdominal pain, persistent indigestion, or a history of ulcers, so testing for H. pylori can be considered. Seek emergency care immediately if you vomit blood or material that looks like coffee grounds, pass black or tarry stools, or have sudden severe abdominal pain, as these can signal a bleeding or perforated ulcer.

Related Topics

Frequently Asked Questions

References

1. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Helicobacter pylori (H. pylori) and Peptic Ulcers.
2. Centers for Disease Control and Prevention (CDC). Helicobacter pylori.
3. Mayo Clinic. Helicobacter pylori (H. pylori) infection.
4. MedlinePlus, U.S. National Library of Medicine. Helicobacter pylori infections.