H. pylori Testing: Blood, Stool and Breath Tests Explained
A burning pain high in the tummy, bloating after meals, indigestion that keeps coming back. Plenty of things cause symptoms like that. One of the most common is a bacterium called Helicobacter pylori, and it is one of the few stomach problems where a test can point to a specific cause you can actually treat.
H. pylori lives in the lining of the stomach and survives there by neutralising acid around itself. It is very common, and most people who carry it never get symptoms. For others it causes ongoing gastritis, the inflammation behind a lot of indigestion, and it is the main cause of peptic ulcers. Long-term infection is also a recognised risk factor for stomach cancer, which is why the NHS takes it seriously when it shows up.
If you are reading this because of recurring stomach trouble, the short version is that the type of test matters more than the brand on the box. A blood antibody test and a stool or breath test are not measuring the same thing, and the difference decides whether your result means anything.
What H. pylori tests measure
There are four ways to look for H. pylori, and they do not all answer the same question.
A blood antibody test, sometimes called serology, checks for antibodies your immune system makes against the bacteria. It is the test most private blood test providers sell. Antibodies stay in the blood for months or even years after the infection is gone, so a positive blood result can only tell you that you have been exposed at some point. It cannot separate an active infection from a past one.
A stool antigen test looks for proteins from the bacteria in a stool sample. Because it detects the organism itself, it can tell active infection apart from past exposure. The NHS and NICE guidance treat stool antigen testing as one of the preferred options, alongside the breath test.
A urea breath test works by having you swallow a small amount of urea and then testing your breath. If H. pylori is present, it breaks the urea down and the change shows up in your breath sample. It also detects active infection, and it is the test most GPs use when they want a quick answer.
An endoscopy with a biopsy is the invasive option. A specialist passes a camera down the throat and takes a tissue sample from the stomach lining. This is usually reserved for cases where a GP wants to look at the stomach directly or where other tests have not settled the question.
The clearest split to remember: blood tests show exposure, while stool and breath tests show what is happening now. If your goal is to find out whether you currently have H. pylori, a blood antibody test on its own is the weaker choice.
Why the timing of a test matters
Two things can produce a false negative on a stool or breath test, and they are easy to get wrong.
Proton pump inhibitors, the acid-reducing medicines sold as omeprazole, esomeprazole and similar, can suppress the bacteria enough to hide it. Guidance from the UK Health Security Agency says stool and breath tests should not be done within two weeks of taking a PPI. Antibiotics can do the same, and the same guidance asks for a four-week gap after antibacterial treatment.
If you are on either, tell the provider before you book. A test taken at the wrong time can come back negative when the infection is still there, and that is worth avoiding because treating H. pylori properly clears it in most people.
NHS appointment or a private test?
If you have persistent stomach symptoms, the NHS is the sensible first stop. Your GP can assess the whole picture, arrange the right test on the NHS, and prescribe treatment if the result is positive. That last part matters: H. pylori is treated with antibiotics, so a positive result without a clinician to prescribe them leaves you stuck.
A private test makes more sense if you cannot get a GP appointment soon, want to check a specific marker quickly, or are already comparing options and want a number before you speak to anyone. It should sit alongside NHS care, not replace it.
What a private H. pylori test costs in the UK
Prices vary by provider and by whether a sample is taken at a clinic or posted to you. Our current comparison data covers these options:
| Provider | Test | Method | Price | Link |
|---|---|---|---|---|
| Bluecrest Wellness | Stomach Cancer (H. Pylori) | Blood antibody, clinic | £65 | View test£65 |
| Goodbody Clinic | Helicobacter Pylori Blood Test | Blood antibody, clinic or home nurse visit | £105 | View test£105 |
| Better2Know | H. Pylori Stomach Ulcer | Blood antibody, home finger-prick | £110 | View test£110 |
| Better2Know | Helicobacter Pylori | Blood antibody, clinic or home nurse visit | £175 | View test£175 |
| Randox Health | H. Pylori Test | Urea breath test, clinic | £120 | View test£120 |
| Lola Health | H Pylori Ab | Blood antibody, add-on to a Lola panel | £35 | View add-on£35 |
Most of these are antibody blood tests, which reflects what the private market mostly sells. Randox is the exception with a breath test, which is the type that can confirm an active infection. Lola’s marker is an add-on and needs one of their main tests alongside it.
MyHealthChecked sells a rapid stool test for around £10, usually in-store at Boots, which gives a quick screening result rather than a lab-confirmed one. It is cheap, but a stool antigen test run in a lab is the version with more weight behind it.
To see how the options line up, you can compare H. pylori tests by price, or browse stomach and gut tests if you want to widen the search. The H. pylori test page lists every provider that sells one.
What a positive result means
A positive result on a stool or breath test points to an active infection. The standard treatment is a course of antibiotics taken with a proton pump inhibitor, usually for a week. Your GP decides the exact combination, partly based on any antibiotics you have taken before.
Once treatment finishes, the infection is not confirmed gone just because symptoms settle. Retesting with a stool or breath test, at least four weeks and ideally eight weeks afterwards, is how you check it worked. A blood antibody test is the wrong tool for that follow-up, because the antibodies linger and can still show positive even after successful treatment.
Two courses that do not clear it warrant a referral to a gastroenterologist, who can look at resistance and other options.
If your stomach symptoms continue after treatment
Do not assume the test was wrong, and do not self-prescribe a second course of antibiotics. Take the result to your GP and work through what else could be going on. Coeliac disease, iron deficiency, thyroid problems and irritable bowel syndrome all produce overlapping symptoms, and it is easy to fix on one cause and miss another.
If you take anti-inflammatory painkillers such as ibuprofen regularly, that is worth raising too. They can irritate the stomach lining on their own and make an ulcer more likely, whether or not H. pylori is involved.
Seek urgent help for severe or worsening abdominal pain, vomiting blood, black or bloody stools, or difficulty swallowing. Those are not symptoms to sit on while waiting for a test result.
A few practical points before you book
- Check whether you have taken a PPI in the last two weeks or antibiotics in the last four. If so, wait or ask the provider’s advice first.
- Ask which test you are actually buying. If the answer is a blood antibody test, understand that it shows exposure, not active infection.
- If your result is positive, line up a GP appointment before you treat anything.
- Keep the report. If a GP arranges a retest, the earlier result gives useful context.
- Do not stop prescribed stomach medication on your own to make a test possible. Talk to a clinician about timing instead.
When Not to Test
A blood antibody test cannot tell you whether the infection has gone. Antibodies linger for months or years after successful treatment, so a positive result afterwards does not mean H. pylori is still there, and a stool antigen or breath test at least four weeks after finishing antibiotics is the way to check. Timing matters just as much: a stool or breath test taken within two weeks of a PPI or four weeks of antibiotics can come back negative while the infection is still present. If you have no symptoms, there is little reason to test at all, since most people who carry H. pylori never develop problems. And do not try to settle this with a home kit if you have lost weight without trying, are vomiting blood, are passing black or bloody stools, or are finding it hard to swallow. Those need a GP urgently, and possibly an endoscopy.
Header image from Pexels
This article is for general information and does not replace advice from a GP or other qualified healthcare professional.
Prices and availability can change. Check the provider’s website before booking.