What is Helicobacter pylori?

Helicobacter pylori or H. pylori is a type of bacteria that infects the lining of the stomach. It is spread through contaminated food and water and through direct mouth-to-mouth contact. In most populations, the bacteria is first acquired during childhood.  

H. pylori has coexisted with humans for many thousands of years, and infection with this bacteria is common. It is estimated that approximately two-thirds of the world's population harbours this bacteria, according to the Centres for Disease Control and Prevention (CDC).

What gastric problems does Helicobacter pylori cause?

Although H. pylori infection does not cause illness in most infected people, it is a major risk factor for peptic ulcer disease and is responsible for the majority of ulcers of the stomach and upper small intestine. 

H. pylori weakens the protective mucus coating of the stomach and duodenum which allows acid to go through to the sensitive lining beneath. Both acid and bacteria irritate the lining and cause a sore or ulcer.

Because of the long-lasting irritation that it can produce in the stomach lining, H. pylori can also increase the risk of some cancers, including stomach cancer, or gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Even though millions of people around the world are infected with these bacteria, only very few (between 1 and 3 out of 100) go on to develop stomach cancer. Researchers think this is because some types of H. pylori are more likely to cause problems than others.

What are the symptoms of H. pylori infection?

Most people with H. pylori infection might never have any signs or symptoms. Also, it is believed that some people may be born with increased resistance to the harmful effects of H. pylori. However, when signs and symptoms of H. pylori are present, they are typically related to gastritis, or peptic/stomach ulcer, and may include:

• An ache or burning pain in your stomach (abdomen)
• Stomach pain that may be worse when your stomach is empty
• Nausea
• Loss of appetite
• Frequent burping
• Bloating
• Unintentional weight loss

But stomach/peptic ulcers aren't always painful and some people may experience other symptoms, such as indigestion (that does not respond to over-the-counter or other medication), heartburn and acid reflux and feeling sick.

You should see your doctor if you notice any signs and symptoms that may be gastritis or a peptic ulcer. Also, seek immediate medical help if you experience severe or ongoing stomach pain that may awaken you from sleep, bloody or black tarry stools, bloody or black vomit or vomit that looks like coffee grounds.

How is Helicobacter pylori diagnosed?

• Blood test - your blood is tested for antibodies to the H. pylori bacteria
• A stool antigen test - a small stool sample is tested for the bacteria
• A urea breath test - you'll be given a drink containing urea (which is a chemical that's broken down by H. pylori), and your breath will be checked after
• Endoscopy - this is when a scope with a camera is passed through your mouth and into your stomach. Biopsies can be taken of the lining of your stomach and tested for H. pylori

All tests for Helicobacter pylori, except the blood test, may be quite inaccurate if you have had a recent course of antibiotics for any reason, or have taken some of the other drugs which are used to treat ulcers.

If you test positive for H. pylori, you'll need treatment to clear it, which can heal the ulcer and prevent it from returning.

References and Further Reading:

https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/h-pylori-fact-sheet

https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/infections-eg-hpv-and-cancer/does-hpylori-cause-cancer - keyreferences

https://www.mayoclinic.org/diseases-conditions/h-pylori/symptoms-causes/syc-20356171

https://www.nhs.uk/conditions/stomach-ulcer/