Do I need a stool test for Helicobacter pylori?

Do you experience pain and discomfort in your stomach around mealtimes? Indigestion can really impact your quality of life and stop you from fully enjoying your food. Did you know that your symptoms could be caused by infection with a common bug, Helicobacter pylori? Let’s dive into what Helicobacter pylori is, the problems and symptoms it can cause and how to test yourself to find out if you have it.

H. pylori is a bacteria which tends to infect the stomach and the very first part of the small bowel called the duodenum. In 1982 two scientists found the link between H. pylori and stomach inflammation. But their findings weren’t believed at first.

Robin Warren was a pathologist who noticed a mystery bacteria in his microscope slides of stomach inflammation and ulcers (figure 1). This bacteria was Helicobacter pylori.

At that time, it was thought that stomach inflammation and ulcers were due to stress or spicy foods. When Warren and his colleague Barry Marshall suggested that H. pylori could be causing stomach inflammation, it was seen as impossible.

To prove their idea, Barry Marshall carried out a famous self-experiment. Marshall decided to make himself a guinea pig and drank a culture of H. pylori bacteria. Shortly afterwards, he suffered indigestion and painful stomach ulcers. Oddly enough, this was great news! They could prove a link between H. pylori infection and developing stomach inflammation¹.

Marshall and Warren received the 2005 Nobel Prize in Physiology for their discovery. Since then, scientists have learned more and more about the importance of Helicobacter pylori in stomach inflammation.

H. pylori infection causes three main problems in the stomach and duodenum - inflammation, peptic ulcers and cancer.

Inflammation in the stomach or duodenum is called gastritis or duodenitis and infection with H. pylori is a major cause². (As Barry Marshall found out the hard way!). H. pylori releases enzymes which weakens your stomach’s protective lining, making it prone to damage by harsh stomach acid.

If gastritis or duodenitis is severe or prolonged, inflammation can develop into peptic ulcers². These are painful sores on the lining of your stomach or duodenum. H. pylori infection is thought to be associated with about 80% of duodenal ulcers^{3, 4} and 60% of gastric ulcers⁵.

If inflammation caused by H. pylori goes on for a long time it can eventually lead to stomach cancer (also called gastric cancer)^{2, 6}. Although stomach cancer is rare, it’s the commonest cancer caused by an infection⁷. As a result, the World Health Organisation has classed H. pylori as a major risk factor for stomach cancer⁸.

H. pylori infection is very common. Around half the world’s population are thought to be infected with H. pylori. Infection rates are lower in more developed nations and 1 in 4 to 1 in 3 people in the UK are thought to have H. pylori^{9, 10}.

We still don’t fully understand how H. pylori spreads between people but it’s likely that the bacteria passes through saliva, stool or contaminated food and drink^{11, 12}. If you’re in close contact with someone with H. pylori - in the same household for example - then you’re at higher risk of having the infection yourself.

How can you tell if you’ve been infected with H. pylori?

Just because you're asymptomatic, i.e. have no symptoms, it doesn’t mean you don't have H. pylori. Studies have shown that many of us can be infected with H. pylori without having any symptoms¹³. Even though most people with H. pylori won’t have symptoms, they can still often have inflammation in the stomach. H. pylori infection (including without symptoms) can increase your chance of developing stomach cancer if you're in an at-risk group, for example having a first-degree relative with stomach cancer^{14, 15}.

One of the common symptoms of H. pylori infection is indigestion, also called dyspepsia. This is pain or burning in the upper middle part of the abdomen (stomach area) and it can happen before, during or after eating.

Indigestion can also come with lots of other symptoms. For example, you might notice heartburn, nausea, vomiting, bloating or feeling full after eating very little.

Another sign that you could have H. pylori infection is actually anaemia. Anaemia means that you have a low haemoglobin level in your blood. Gastritis caused by H. pylori can make it more difficult for your body to absorb iron from your diet. Both gastritis and ulcers can also cause bleeding in your gut which means you lose iron with the blood¹⁶.

If your iron level is low, your body can’t make enough haemoglobin and you have so-called iron-deficiency anaemia. Anaemia can make you feel weak, tired and occasionally breathless. If you want to learn more about anaemia, you can read our article on anaemia.

Unexplained weight loss can be a cause for concern at any age but if you’re aged 55 and over, unexplained weight loss can be a sign of gastric cancer¹⁷. If you’re aged 55 or above and you’ve experienced indigestion with unexplained weight loss, it’s worth discussing this with a healthcare professional.

How do H. pylori tests work and what do they involve? The National Institute for Health and Care Excellence (NICE) recommends either a breath test or a stool antigen test to diagnose H. pylori infection¹⁸, but it’s also worth being aware of some of the other available tests.

With all of these tests, it’s important that you’re not taking proton pump inhibitor (PPI) medication when you do the test. These are quite common “antacid” medications that are actually used to treat H. pylori and make tests less effective.

The H. pylori stool antigen test is recommended by NICE and is commonly used by GPs and hospital doctors¹⁸. We also provide the stool antigen test for H. pylori infection and you can have it delivered straight to your door.

The Helicobacter pylori stool antigen test uses a simple kit for you to take a stool sample at home. Then you just post your stool sample off to our lab for analysis. You’ll get a “positive” or “negative” result back within a few days along with advice from one of our doctors.

Stool antigen tests are great for identifying active infection. Most studies report the test sensitivity as being above 90%. This means that 9 in every 10 people who have H. pylori will be picked up by this test^{19, 20, 21}.

Urea breath tests are also recommended by NICE for diagnosing H. pylori infection¹⁸. However, they need to be done in a hospital and require large instruments to measure compounds in your breath.

In general, blood tests for H. pylori infection are not recommended because they may be positive if you’ve had H. pylori in the past, even if you don’t have it now²².

H. pylori infection can also be diagnosed during a camera test of the stomach. This is a very good test but it needs to be done in hospital.

You might be wondering whether you should test for H. pylori infection. In general, there are two main groups of people who should get tested for H. pylori - those who have symptoms and those who are at high risk of problems if they get H. pylori.

If you’re experiencing symptoms of indigestion, such as nausea, vomiting, bloating or pain in the upper part of your stomach around mealtimes, H. pylori infection could be to blame. We would recommend getting tested for H. pylori to find out if infection is the cause.

H. pylori can cause major problems like peptic ulcers and gastric cancer. Studies have shown that testing and treating H. pylori infection can reduce the risk of having these problems even when people don’t have symptoms like indigestion^{14, 15}. Testing and treating people without symptoms like this is called “screening”.

However, because major problems with H. pylori are relatively rare in most people, it’s only cost-effective to screen large groups of people if they're particularly high-risk. Higher risk groups would include older people taking aspirin or ibuprofen, and people with a first-degree relative who has gastric cancer.

If you’re not in a high-risk group then screening for H. pylori is generally not recommended. However, if you do decide to test for H. pylori and are found to have it, the expert recommendation is that you get treated¹⁴.

Do you relate to some of the symptoms of H. pylori we’ve discussed or want to test yourself even if you don’t have symptoms? You can find our Helicobacter pylori Stool Antigen Test here. You can read our helpful how to take your stool test article to get some advice on how to actually take a stool sample - it’s pretty simple.

Remember that indigestion and related symptoms are common and can be caused by other conditions than H. pylori infection. For example, coeliac disease, where your gut lining becomes damaged after eating gluten, causes very similar indigestion symptoms to H. pylori infection. Because of the overlapping symptoms, we have a Coeliac and H. pylori Combined Test for Indigestion which tests for both H. pylori and coeliac disease together in one go.

If you do receive a positive result and are infected with H. pylori, our doctors will give you advice on what to do next.

Treatment for H. pylori infection usually involves a short course of antibiotics and proton pump inhibitors for 7 to 10 days¹⁸. You can get a treatment course prescribed by your doctor.