TL;DR — Bottom Line
- Helicobacter pylori is a treatable bacterial infection and the dominant cause of peptic ulcer disease. It is also classified as a Group 1 carcinogen for gastric cancer, which is why eradication matters beyond symptom relief.
- Urea breath test and stool antigen detect active infection. Antibody blood tests cannot distinguish current infection from one cleared years ago, which makes them a poor choice for most people.
- Stop proton pump inhibitors two weeks before testing and antibiotics or bismuth four weeks before. Failing to do this is the most common cause of a false negative.
- Treatment requires prescription antibiotics — typically a combination regimen. No supplement eradicates H. pylori, and the ones marketed for it have no eradication evidence.
- Confirm eradication after treatment. A test of cure at least four weeks after finishing antibiotics is standard, because regimens fail more often than people assume.
Quick Picks
Helicobacter pylori is a spiral bacterium that colonises the stomach lining, where it survives the acid by producing urease to neutralise its immediate environment. It is one of the most common chronic bacterial infections in humans, and most people who carry it never develop symptoms.
In a minority it causes chronic gastritis, peptic ulcers, and in a smaller subset gastric adenocarcinoma or MALT lymphoma. It is the only bacterium classified by the International Agency for Research on Cancer as a Group 1 carcinogen. That combination — common, usually silent, occasionally serious, and reliably curable with antibiotics — is what makes accurate testing worth getting right.
H. Pylori Tests Compared
| Urea breath test | Stool antigen | Antibody serology | |
|---|---|---|---|
| Detects | Active infection | Active infection | Past or present exposure |
| How it works | Labelled urea split by bacterial urease | Bacterial antigens in stool | IgG antibodies in blood |
| Accuracy for active infection | High | High | Poor — cannot distinguish |
| Affected by PPIs | Yes — stop 2 weeks | Yes — stop 2 weeks | No |
| Use for test of cure | Yes — preferred | Yes | No — antibodies persist |
| Home sampling | Yes, with breath bags | Yes | Yes |
Why Antibody Tests Are Usually the Wrong Test
Serology detects IgG antibodies to H. pylori, and those antibodies can persist for years after the infection has been eradicated. A positive result therefore means you have been infected at some point, which in populations with high background prevalence is not a useful piece of information and frequently leads to treating someone who no longer carries the bacterium.
There is a narrow situation where serology has a role: it is unaffected by proton pump inhibitors and antibiotics, so it can be used in someone who cannot stop those medications. Outside that case, and outside epidemiological research, breath or stool testing is what you want.
How the Urea Breath Test Works
H. pylori produces large amounts of urease, an enzyme that splits urea into ammonia and carbon dioxide. The breath test exploits this directly: you swallow urea labelled with a carbon isotope, and if the bacterium is present, the labelled carbon dioxide it releases appears in your breath within minutes. Breath samples before and after are compared.
It is a clean, mechanistic test with excellent sensitivity and specificity for active infection, and it is the preferred method for confirming eradication after treatment. Home versions collect breath into sealed bags for laboratory analysis. The procedure has more steps than a stool sample and following them precisely matters.
The Medication Washout That Ruins Most Home Tests
Proton pump inhibitors — omeprazole, lansoprazole, esomeprazole and their relatives — suppress H. pylori without eradicating it, reducing the bacterial load below the detection threshold of both breath and stool tests. Standard guidance is to stop them for two weeks before testing. H2 blockers such as famotidine have a smaller effect and are often permitted closer to the test; antacids are generally acceptable.
Antibiotics and bismuth compounds require a longer washout, commonly four weeks, for the same reason. Someone who has recently taken antibiotics for an unrelated infection and then tests can easily produce a false negative. If you cannot safely stop acid suppression, discuss it with a clinician rather than testing anyway and trusting the result.
What Happens After a Positive Result
Eradication requires a combination of prescription antibiotics with acid suppression, typically two antibiotics plus a proton pump inhibitor, or a bismuth-containing quadruple regimen, taken for one to two weeks. Which regimen is appropriate depends on local antibiotic resistance patterns, which vary considerably by region, and on your own antibiotic history. This is a prescribing decision.
Nothing sold over the counter eradicates H. pylori. Products marketed for it — mastic gum, certain probiotics, broccoli sprout extract — have some in vitro or small-study evidence for reducing bacterial load or improving tolerance of treatment, and none has eradication evidence that would justify using it instead of antibiotics. Some probiotics have reasonable evidence for reducing the side effects of eradication therapy, which is a genuine but different claim.
Test of Cure Is Not Optional
Eradication regimens fail more often than most people expect, largely because of rising clarithromycin and metronidazole resistance. Guidelines therefore recommend confirming eradication after treatment, using a urea breath test or stool antigen test at least four weeks after finishing antibiotics and with the PPI stopped for two weeks.
This is the step most commonly skipped, and skipping it means someone who believes they are cured continues carrying a Group 1 carcinogen. Serology cannot be used for this purpose, since the antibodies persist regardless.
Test Types Worth Considering
The meaningful distinction is between tests that detect active infection and tests that detect past exposure. Within the first group, choose on convenience.
Urea Breath Test Kit
The most accurate non-invasive test for active infection and the preferred method for confirming eradication after treatment. You collect breath samples before and after swallowing labelled urea, and the sealed bags go to a laboratory. Follow the fasting and washout instructions exactly — two weeks off proton pump inhibitors and four weeks off antibiotics or bismuth is what makes the result mean anything.
Who it is for: anyone testing for active H. pylori infection, and anyone confirming eradication after a treatment course.
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Shop H. Pylori Urea Breath Test Kits on AmazonStool Antigen Test Kit
Detects H. pylori antigens shed in stool, with accuracy for active infection comparable to the breath test and a considerably simpler collection procedure. It is subject to the same medication washout requirements, which people often assume applies only to breath testing. A reasonable first choice for most home testing, and valid as a test of cure.
Who it is for: people who want the simplest accurate home test for active infection.
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Shop H. Pylori Stool Antigen Test Kits on AmazonH. Pylori Antibody Blood Test
Detects IgG antibodies, which persist for years after eradication, so a positive result cannot distinguish an active infection from one cleared a decade ago. Its one genuine advantage is that it is unaffected by proton pump inhibitors and antibiotics, making it usable in someone who cannot stop those medications. Otherwise it is the wrong test and will lead to unnecessary antibiotic courses.
Who it is for: people who cannot safely stop acid suppression for the washout period, and nobody else.
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Shop H. Pylori Antibody Blood Test Kits on AmazonProbiotics for Eradication Therapy Tolerance
Certain probiotic strains, notably Saccharomyces boulardii and some lactobacilli, have reasonable trial evidence for reducing the diarrhoea and gastrointestinal side effects of H. pylori eradication regimens, and better tolerance improves the completion rates that determine whether treatment works. This is an adjunct to antibiotics and explicitly not a replacement — no probiotic eradicates the infection.
Who it is for: people already prescribed an eradication regimen who want to complete the full course.
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Shop Saccharomyces Boulardii Probiotics on AmazonBland Diet and Reflux Support Supplies
While waiting for testing or treatment, symptom management is reasonable and does not interfere with a stool or breath test the way acid suppression does. Antacids are generally permitted closer to testing than PPIs, and simple measures — smaller meals, avoiding late eating, raising the head of the bed — help. Check kit instructions for what is permitted during your specific washout.
Who it is for: people managing gastritis symptoms during the washout period before testing.
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Shop Antacids and Reflux Wedge Pillows on AmazonWhich One Fits Your Situation
H. pylori is one of the more satisfying findings in gastroenterology precisely because it is curable. A common chronic infection, causally linked to ulcers and to gastric cancer, cleared by a one to two week course of antibiotics, is not a situation that calls for cautious hedging.
The two things that most often go wrong are testing on a proton pump inhibitor and getting a false negative, and never confirming eradication afterward. Both are avoidable with a calendar and neither costs anything.