H. Pylori Infection and How It Affects Your Stomach

The Biomarker Handbook is a curated series that seeks to provide readers with insights on each biomarker we cover in our blood test packages and its relation to our body.

You might find this little piece of history very interesting. Helicobacter pylori (H. pylori) is a type of bacterium that is primarily found in the stomach. The bacterium was identified in 1982 by two Australian Scientists, Barry Marshall and Robin Warren. Greatly disturbed by seeing stomach ulcer patients suffer from agonizing pain, have their stomachs resected, or even bleed to death, they set out to discover the cure for ulcers. They biopsied tissues from patients with stomach ulcers and traced not only the ulcers but also cancerous cells to H. pylori bacteria.

Out of desperation, Barry isolated H. pylori from an ailing patient, stirred it in broth and consumed it. As days passed, Barry developed gastritis, vomited frequently, had bad breath, and felt extremely sickly. They biopsied Barry’s stomach and isolated  H. pylori, proving that the bacterium was the underlying cause of ulcers. In 2005, Barry and Robin shared a Nobel Prize for their discovery.

According to the CDC, H. pylori is the cause of 90% of all duodenal ulcers and 80% of all stomach ulcers. Recent studies also show an association between stomach cancer and long-term infection with H. pylori. It is also the cause of atrophic gastritis, which is a known precursor for stomach cancer- and some doctors are now even treating asymptomatic H. pylori infected people as a preventative measure against developing stomach cancer, although no studies support this thesis yet.

How common is H. pylori and is it contagious?

  1. H. pylori is common globally, and about 50% of the world is affected. The prevalence rates are higher in developing and underdeveloped countries, with most infections beginning from childhood. Poor hygiene practices, food prepared in less than ideal conditions, crowded living conditions, and use of contaminated water, increases the likelihood of the infections.
  2. H. pylori can be transmitted from one person to another through contaminated body fluids. The most common routes of infection are oral to oral and fecal-oral. Maintaining hygiene, proper food handling, proper handwashing techniques, using clean, safe water and seeking treatment early are therefore the mainstay of preventing and controlling H. pylori.

Why track Helicobacter pylori?

Unlike most bacteria, H. pylori colonize the gut for life, unless specific treatment is administered. Thanks to several properties, H. pylori can persist in our highly acidic gastric environment.

  1. The bacteria produce an enzyme called urease which raises the pH and protects itself from the acid environment.
  2. The spiral shape of H. pylori also makes it easier for it to propel towards the epithelium (outermost layer) of the stomach lining and burrow into it, where there is a near-neutral pH.
  3. The outer membrane of the bacterium is covered with a type of fatty acid that facilitates it to evade the body’s immune response.

These factors allow H. pylori to survive in the stomach and cause prolonged, devastating effects. There is therefore a need to detect the infection and treat it early before the results become detrimental.

Tracking is also necessary for:

  • Suspected stomach or duodenal ulcer
  • Suspected gastritis (inflammation also commonly associated with H. pylori)
  • History of duodenal ulcer in the past
  • After treatment of H. pylori infection, to see if the bacteria was eradicated

Ways to detect H. pylori

Several methods of testing H. pylori exist. Non-invasive tests include a stool antigen test, a urea breath test and a blood test for antibody. Invasive tests to obtain the stomach tissue for examination are indicated when there is need to visualize the gut or cancer is suspected.

Non-invasive methods are the most commonly used.

Breath Test (carbon isotope-urea breath test (UBT))

  • One is given a capsule containing carbon isotope. If H. pylori bacteria are present, they convert urea into ammonia and carbon dioxide.
  • Samples of the exhaled air are collected to detect the amount of isotopic carbon in the exhaled carbon dioxide. If isotopic carbon is detected, then H. pylori are present.
  • A breath test can tell if H. pylori bacteria are presently active in the gut, and also can be used to check if the infection has been adequately treated. This makes the urea breath test reliable for diagnosing and monitoring treatment of active H. pylori infections.

IgG antibody test

  • Blood is obtained to detect antibodies released in response to H. pylori
  • The drawback of the antibody test is that it cannot tell if the patient has a current (or past) infection and for how long it has been present. The antibodies can remain in the blood for long after the infection has cleared. As a result, the test can remain positive for years. Thus, it cannot be used to tell whether the infection is active and whether treatment is effective. However if the antibody test is negative, then it is clear that there is no H. pylori infection.


  • A gastroscopy (visual examination of the stomach by means of a tube inserted through the esophagus) can be performed if there is suspicion of peptic ulcer, cancer or precancer (early cellular changes that if left untreated can turn into cancer). It is a commonly performed procedure, during which the enterologist takes a sample biopsy of the lesion or stomach cells to look for H. pylori and abnormal or cancer cells.

Signs and symptoms to watch out for

Up to 85% of people infected with H. pylori do not experience any symptoms. When symptoms occur, they may include:

  • Upper abdominal pain
  • Frequent burping and bloating
  • Unintended weight loss
  • Loss of appetite
  • Nausea and vomiting

The symptoms are worse in the morning or when the stomach is empty.

Complications of Helicobacter pylori

Infection by H. pylori is a major cause of peptic ulcers (90% of stomach ulcers are positive for H. pylori) and is also strongly associated with chronic gastritis and stomach cancer.

When the bacteria enters the digestive tract, it invades the stomach lining and causes chronic inflammation, known as gastritis. The bacteria also produces a cytotoxin known as vacuolating cytotoxin A (Vac-A), resulting in an ulcer formation. H. pylori also cause alterations of the cells of the stomach, increasing the risk for stomach cancer. H. pylori account for about 5.5% of all cancers and 25% of infection-related cancers.

Ways to balance H. pylori

There are several claims on natural remedies of H. pylori infections, but they remain subject to scientific proof. They include the use of:

  • Garlic
  • Broccoli
  • Green tea
  • Liquorice
  • Honey
  • Probiotics
  • Mastic Gum

Nutritionists and other healthcare providers also suggest the following ways to ease the symptoms and prevent the spread of the infection:

  • Avoiding spicy food, alcohol, smoking and carbonated drinks
  • Eating small regular portions of meals
  • Eating properly cooked food
  • Handwashing before eating and after using the washroom
  • Drinking clean and safe treated water
  • Limit use of aspirin and NSAIDs such as ibuprofen

Medical management of H. pylori

Management of H. pylori poses some challenges because it is capable of developing resistance to commonly used antibiotics. A combination of two or more antibiotics together with a Protein Pump Inhibitor (PPI) and/or bismuth-containing compounds is recommended as the first-line treatment. The antibiotics may be amoxicillin, clarithromycin, metronidazole or tetracycline while the PPIs may be omeprazole, lansoprazole, rabeprazole, pantoprazole or esomeprazole.

After the treatment, a urea breath test is done to confirm eradication of H. pylori. If not eliminated, a different combination may be used.

When to see the doctor

The following symptoms require medical attention, and should not be ignored:

  • Severe persistent abdominal pain
  • Difficulty in swallowing
  • Bloody or coffee ground vomit
  • Bloody or black tarry stool

Further tests that may be performed

Stool test

  • A stool test can detect traces of H. pylori in the feces
  • It can be used to determine whether the infection is active or whether treatment is effective
  • Best for children as it does not have any instructions to be followed


  • A tissue sample is taken from the stomach lining through a procedure known as endoscopy, then taken for examination.
  • Endoscopy also allows visualization of the stomach lining, to determine the severity of gastritis, ulcer or cancer.
  • Used in combination with a urea breath test or stool test.


Although H. pylori affects more than half of the global population, there is a ray of hope as the infection is both preventable and treatable. Quick detection and treatment help to prevent the damage to the stomach lining and possible complications like ulcers, chronic gastritis, and stomach cancer.

According to recent studies, the use of prophylactic (preventative rather than curative) eradication to stop the development of gastric cancer or peptic ulceration in H pylori– positive but asymptomatic individuals should be considered only in research settings. We do not have conclusive evidence to support the perceived benefits of eliminating this bacteria from our asymptomatic stomach weighing with the potential costs of antibiotic resistant H. pylori which can be increased due to rampant usage (50% of us have the bacteria and 80% are asymptomatic!). If you have any upper gastrointestinal symptoms then see your doctor regarding H. pylori screening. If not, you can still consult your doctor and seek advice regarding your own screening and prophylactic treatment as your own situation merits (family history of stomach cancer, etc.).

If you want to find out more about helicobacter pylori infection and how you can balance H. pylori, take a look at our lifestyle article here!

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