Helicobacter pylori

Also called H. pylori

Helicobacter pylori (H. pylori) is a type of bacteria that can infect your gut (stomach). It is a common cause of dyspepsia (indigestion) and peptic ulcers. H. pylori can be treated with 2 antibiotics plus another type of medicine called proton pump inhibitor (PPI).

What is H. pylori infection?

H. pylori bacteria can infect your gut through contaminated food or water. There is greater risk of spread in areas with overcrowded living conditions, poor hygiene and unsafe drinking water. The bacteria are usually picked up in childhood; it is very rare to pick them up as an adult. The bacteria damages the protective lining of your stomach and causes it to produce more acid. This can increase the chance of developing:

Most people have H. pylori bacteria in their gut, but do not have any symptoms. Only some people will go on to get indigestion, dyspepsia and ulcers. 

H. pylori infection in New Zealand

In New Zealand, the rate of H. pylori infection is lower than many other developed countries, with an average rate of 18.6%. However, this rate varies depending on ethnic group:

  • For New Zealand Europeans, about 7 in every 100 people are infected, which ranks among the lowest rates for H. pylori in the world.
  • In non-Pakeha communities the rate is higher: Māori, about 35 in every 100 people, Pasifika, about 30 in every 100 people, Asian, about 24 in every 100 people and Indian, about 10 in every 100 people. These rates can vary considerably (20% to 35%).

How is H. pylori diagnosed?

If you have symptoms of dyspepsia (indigestion) and peptic ulcers your doctor may test for H. pylori bacteria. This can be done by testing a stool (faeces or poo) sample.  

H. pylori can also be tested using a breath test or blood test but these are not commonly used in New Zealand. 

Who should be tested for H. pylori?

People with a duodenal ulcer, stomach ulcer and with ongoing or frequent symptoms of dyspepsia

How is H. pylori infection treated?

Eradication therapy

H. pylori bacteria can be treated by taking two antibiotics and another type of medicine called proton pump inhibitor (PPI). The antibiotics kill the bacteria and the PPIs reduce your stomach acid so the antibiotics can work well. This combination of medicines is often called 'eradication therapy'.

You will need to take eradication therapy for 14 days. It is important to take all the medication exactly as directed and to finish the course.  

Eradication therapy clears H. pylori for 9 out of 10 people if it is taken correctly for the full course. If you don't take the full course of medication, then it will not work so well. A second course of eradication therapy, using different antibiotics, will usually work if the first course hasn't cleared the infection.

What about side effects?

Up to 3 in 10 people have some side effects when they take eradication therapy. These include indigestion, feeling sick (nausea), taste disturbances, diarrhoea (runny poo) and headaches. These side effects will usually pass after a few days. 

Can I be re-infected?

Once you have had successful treatment of H. pylori, the chance of being re-infected is very low because most infections occur in childhood. It is very rare to get it as an adult. 

How can I prevent H. pylori infection?

The exact way that H. pylori bacteria is spread between people is not fully understood, but good hygiene may reduce the spread. This includes:

  • washing your hands with soap and water after going to the toilet and before eating
  • eat only food that has been washed well and cooked properly
  • drinking water only from a clean, safe source.

Learn more

The following links provide further information about H. pylori. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Helicobacter pylori and stomach pain  Patient Info, UK, 2017


  1. The changing face of Helicobacter pylori testing BPAC, NZ, 2014
  2. Helicobacter pylori infection New Zealand Formulary
Credits: Health Navigator Editorial Team. Last reviewed: 28 Aug 2017