Infection with Helicobacter pylori (H. pylori) is the cause of most stomach and duodenal ulcers. H. pylori also causes some cases of non-ulcer dyspepsia. Infection with H. pylori can be confirmed by a test done on a sample of stools (faeces), by a breath test, by a blood test, or from a biopsy sample taken during a gastroscopy (endoscopy). A one-week course of two antibiotic medicines plus an acid-suppressing medicine will usually clear the H. pylori infection. This should prevent the return of a duodenal or stomach ulcer that had been caused by this infection.
What is Helicobacter pylori infection and who is affected by it?
Helicobacter pylori (commonly just called H. pylori) is a germ (bacterium). It can infect the lining of the stomach and duodenum (the first part of the intestine). Over half the world's population has it. It is more common in developing countries. Why and when people become infected is unknown. It is sometimes present in children and some scientists believe we acquire it at a very young age. About 15 in 100 people are infected in the UK and it is becoming less common as time goes by. Once you are infected, unless treated, the infection usually stays for the rest of your life.
Who should be tested for Helicobacter pylori and treated if it is found?
If you have repeated indigestion symptoms (recurring dyspepsia)
If you have recurring dyspepsia (dyspepsia which clears up and then comes back again), it is common practice to test for H. pylori before doing any other tests. If H. pylori is found, eradication treatment is often given. The exact diagnosis may not be known. For example, it might not be clear if the dyspepsia is caused by a duodenal or stomach ulcer, or non-ulcer dyspepsia. These can only be confirmed by having a look down into the gut with a test called gastroscopy (endoscopy). However, if symptoms go after treatment for H. pylori then that is the end of the matter. You do not need further tests such as gastroscopy. You will not know exactly what caused the symptoms but this does not matter if the symptoms have gone.
Other reasons for testing
If you are in one of the following groups, you may be offered a test for H. pylori and offered treatment with eradication therapy if it is found. If you:
- Have a duodenal or stomach ulcer. Eradication therapy will usually cure the ulcer.
- Have non-ulcer dyspepsia. Eradication therapy may work and clear symptoms but it does not in most cases.
- Have a first-degree relative (mother, father, brother, sister or child) who has been diagnosed with stomach cancer. Treatment is advised even if you do not have any symptoms. The aim is to reduce your future risk of stomach cancer.
- Are taking, or are about to take, long-term anti-inflammatory medication such as ibuprofen, diclofenac, aspirin, etc. The combination of these medicines and H. pylori increases the risk of developing a stomach ulcer.
- Have a MALToma.
- Have inflammation of the stomach lining (atrophic gastritis).
- Have had an operation to remove a stomach cancer.
- Have unexplained iron-deficiency anaemia.
- Have a condition called chronic idiopathic thrombocytopenic purpura. This is an uncommon blood condition where the number of platelets in the blood becomes very low. Some research suggests a possible connection between H. pylori infection and this condition.
What problems does Helicobacter pylori cause?
Commonly there are no problems
Most people who are infected with H. pylori have no symptoms or problems caused by the infection. These people do not know that they are infected. A number of H. pylori germs (bacteria) may just live harmlessly in the lining of the stomach and duodenum.
Stomach and duodenal ulcers
H. pylori is the most common cause of duodenal ulcers and stomach (gastric ulcers). About 3 in 20 people who are infected with H. pylori develop an ulcer. An ulcer occurs where the lining of the stomach or duodenum is damaged by the acid made in the stomach and the underlying tissue is exposed.
In some people H. pylori causes inflammation in the lining of the stomach or duodenum. This is called gastritis and may lead to other conditions such as vitamin B12 deficiency. In gastritis the mucous defence barrier appears to be disrupted in some way (and in some cases the amount of acid to be increased). This seems to allow the acid to cause inflammation and ulcers.
This is a condition where you have recurrent bouts of indigestion (dyspepsia) which are not caused by an ulcer or inflammation. It is sometimes called functional dyspepsia. H. pylori is sometimes found in people with non-ulcer dyspepsia. Getting rid of H. pylori cures some cases but makes no difference in most cases. The cause of most cases of non-ulcer dyspepsia is not known.
The risk of developing stomach cancer is thought to be increased with long-term infection with H. pylori. However, it has to be stressed that the vast majority of people with H. pylori do not get stomach cancer. The increased risk is small. Your risk may be greater if you have H. pylori in addition to having a first-degree relative (mother, father, brother, sister or child) who has been diagnosed with stomach cancer.
Gastric mucosa-associated lymphoid tissue lymphoma - a MALToma
This is a rare and unusual type of stomach cancer. Infection with H. pylori is thought play a role in this condition developing.
How is Helicobacter pylori diagnosed?
Various tests can detect H. pylori:
- A breath test can confirm that you have a current H. pylori infection. A sample of your breath is analysed after you take a special drink. Note: prior to this test you should not have taken any antibiotics for at least four weeks. Also, you should not have taken a proton pump inhibitor (PPI) or H2-receptor antagonist medicine for at least two weeks. (These are acid-suppressing medicines.) Also, you should not eat anything for six hours before the test. The reason for these rules is because the medication and food can affect the test result.
- An alternative test is the stool antigen test. In this test you give a pea-sized sample of your stools (faeces) which is tested for H. pylori. Note: prior to this test you should not have taken any antibiotics for at least four weeks. Also, you should not have taken a PPI or H2-receptor antagonist acid-suppressing medicine for at least two weeks.
- A blood test can detect antibodies to H. pylori. This is sometimes used to confirm that you are, or have been, infected with H. pylori. However, it can take up to a year for this test to become negative once the infection has cleared. So, it is no use to confirm whether treatment has cleared the infection (if this needs to be known). If needed, the breath test or stool antigen test is usually used to check if an infection has cleared following treatment.
- Sometimes a small sample (biopsy) of the lining of the stomach is taken if you have a gastroscopy (endoscopy). The sample can be tested for H. pylori.
How is Helicobacter pylori cleared from the stomach and duodenum?
H. pylori is killed by certain antibiotics. However, a combination of medicines is needed to get rid of it completely. This is referred to as combination therapy although because it gets rid of (eradicates) the germ it is also referred to as eradication therapy. You need to take two antibiotics at the same time. In addition, you need to take a medicine to reduce the acid in the stomach. This allows the antibiotics to work well in the stomach. You need to take eradication therapy for a week. It is important to take all the medication exactly as directed and to take the full course.
Eradication therapy clears H. pylori in up to 9 in 10 cases if it is taken correctly for the full course. If you do not take the full course then the chance of clearing the infection is reduced. A second course of eradication therapy, using different antibiotics, will usually work if the first course does not clear the infection.
Eradication therapy is sometimes called triple therapy as it involves three medicines - two antibiotics and an acid-suppressing medicine.
If you have indigestion (dyspepsia), it is usually only necessary to check to see if the H. pylori has gone if your symptoms come back after treatment. If you have a gastric or duodenal ulcer, testing is usually done 6-8 weeks after treatment.
Are there any side-effects of eradication therapy?
Up to 3 in 10 people develop some side-effects when they take eradication therapy. These include indigestion (dyspepsia), feeling sick (nausea), diarrhoea and headaches. However, it is worth persevering with the full course if side-effects are not too bad. A switch to a different set of medicines may be advised if the first combination does not clear the H. pylori, or if it caused bad side-effects and you had to stop taking it.
Further reading and references
Gastro-oesophageal reflux disease and dyspepsia in adults: investigation and management; NICE Clinical Guideline (Sept 2014 - last updated October 2019)
Diaconu S, Predescu A, Moldoveanu A, et al; Helicobacter pylori infection: old and new. J Med Life. 2017 Apr-Jun10(2):112-117.
Dore MP, Pes GM, Bassotti G, et al; Dyspepsia: When and How to Test for Helicobacter pylori Infection. Gastroenterol Res Pract. 20162016:8463614. doi: 10.1155/2016/8463614. Epub 2016 Apr 28.
Dyspepsia - proven functional; NICE CKS, October 2018 (UK access only)
Dyspepsia - proven peptic ulcer; NICE CKS, October 2019 (UK access only)