Helicobacter pylori breath test
By Dr. Bahir Hadi — Consultant Surgeon, PhD
Helicobacter pylori breath test: the simplest test for peptic ulcer
The Helicobacter pylori breath test (¹³C-urea breath test, UBT) is the most accurate non-invasive test for active Helicobacter pylori infection - the bacterium responsible for up to 70 % of all peptic ulcers and a major risk factor for gastric cancer [1]. UBT has sensitivity and specificity >95 % [2] and is first-line for both primary diagnosis and post-eradication confirmation.
How does the breath test work?
- You exhale into a test bag (baseline).
- You drink a small volume of liquid containing ¹³C-labelled urea (non-radioactive).
- You wait 20-30 minutes.
- You exhale into a second test bag.
Principle: H. pylori produces the enzyme urease, which splits urea into CO₂ and ammonia. If the bacterium is present, your exhaled breath contains elevated ¹³CO₂ - measured by mass spectrometry or infrared spectrophotometry.
When is the breath test indicated?
- Dyspepsia without alarm symptoms (test-and-treat) in patients under 55
- Previous peptic ulcer without documented prior eradication
- Family history of gastric cancer (first-degree)
- Iron-deficiency anaemia without other cause
- ITP (idiopathic thrombocytopenic purpura)
- Confirmation 4 weeks after eradication therapy - to verify success
Important - preparation
To avoid false-negative results:
| Substance | Washout period |
|---|---|
| Proton pump inhibitors (PPIs) - omeprazole, pantoprazole | Stop 2 weeks before |
| Antibiotics | Stop 4 weeks before |
| Bismuth compounds | Stop 4 weeks before |
| H2 blockers (ranitidine) | Stop 24 hours before |
| Antacids | Stop 24 hours before |
| Fasting | At least 6 hours before |
Alternatives to the breath test
| Test | Pros | Cons |
|---|---|---|
| Breath test (UBT) | Simple, high accuracy, validated for follow-up | PPI washout required |
| Stool antigen test | As accurate as UBT | Sample handling inconvenient |
| Gastroscopy + CLO/biopsy | Direct visualisation + bacteriology | Invasive, more expensive |
| Serology (blood test) | Fast | Cannot distinguish active from past infection - unsuitable for follow-up |
Treatment if positive
Triple therapy 14 days (first-line):
- PPI (omeprazole 20 mg / pantoprazole 40 mg) twice daily
- Amoxicillin 1 g twice daily
- Clarithromycin 500 mg twice daily
Bismuth quadruple therapy for penicillin allergy or suspected clarithromycin resistance.
Eradication reduces ulcer recurrence from ~60 % to <10 % [3] and halves long-term gastric cancer risk.
Follow-up after treatment
- Breath test or stool antigen test 4 weeks after completed therapy (after 2-week PPI washout).
- If still positive: second-line therapy with new antibiotic combination.
Testing at Kirurgen.dk
We offer ¹³C-urea breath testing in our outpatient clinic, both for primary diagnosis and post-treatment confirmation. If a peptic ulcer or alarm symptoms are present, we combine it with oral or nasal gastroscopy in the same visit. See also: Helicobacter pylori, Peptic ulcer, GERD, Black stool.
References
- Malfertheiner P, Megraud F, Rokkas T, et al. Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report. Gut 2022;71(9):1724-62.
- Gisbert JP, Pajares JM. 13C-urea breath test in the diagnosis of Helicobacter pylori infection - a critical review. Aliment Pharmacol Ther 2004;20(10):1001-17.
- Ford AC, Gurusamy KS, Delaney B, Forman D, Moayyedi P. Eradication therapy for peptic ulcer disease in Helicobacter pylori-positive people. Cochrane Database Syst Rev 2016;(4):CD003840.
More on this topic at Kirurgen.dk
Category: Endoscopy