Helicobacter Forums

Hi everyone, I’m preparing for a urea breath test and was wondering about the impact of common medications. For instance, do proton pump inhibitors, antibiotics, or antacids significantly affect the accuracy of C13 or C14 breath tests? How long should one ideally stop these medications before taking the test to avoid false results?Take Care Of Shadow Milk Any practical tips from personal or clinical experience would be greatly appreciated.

The UBT is essentially a check to the activity of the urease enzyme. H. pylori uses urease to rapidly create a protective ammonia layer, allowing it to survive the stomach's strong acid. The UBT measures the activity of this enzyme by measuring the CO2 produced from the breakdown of urea (the tablet you swallow before UBT).
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If the enzyme activity is suppressed, the test fails, leading to a false negative.

When you PPIs or any medication or herb that significantly reduces stomach acid, the pH level rises. The bacteria no longer feel threatened by the acid and essentially "turn off" their urease because they don't need it in the comfortable, neutral pH environment. This lack of enzyme activity means the UBT will be fooled and show a false negative. Furthermore, raising the pH allows other types of bacteria to thrive in the stomach, and this new crowd of competitor microbes can temporarily suppress the H. pylori population, further lowering the bacterial load available for testing.

Similarly, antibiotics and even bismuth preparations are designed to actively kill and suppress the H. pylori population. If you take them too close to the test, they can reduce the number of bacteria to such a low level that there aren't enough of them making urease for the test to pick up a signal. For these reasons, you must stop taking PPIs for two weeks, and antibiotics for about four weeks, before a UBT. This pause gives any remaining H. pylori a chance to recover, multiply, and turn their urease enzyme back on, ensuring that the test provides an accurate snapshot of the true infection status.

PPIs and antibiotics can definitely cause false-negatives, so most clinics have you stop PPIs for 2 weeks and antibiotics for 4 weeks before a urea breath test. Antacids don’t matter much. Best to follow those timelines for an accurate result.

skylerclooney wrote: Wed Sep 24, 2025 5:49 pm Hi everyone, I’m preparing for a urea breath test and was wondering about the impact of common medications. For instance, do proton pump inhibitors, antibiotics, or antacids significantly affect the accuracy of C13 or C14 breath tests? How long should one ideally stop these medications before taking the test to avoid false results?Kart Bros IO Any practical tips from personal or clinical experience would be greatly appreciated.

Hi everyone, I’m preparing for a urea breath test and was wondering about the impact of common medications.

you should not take anything that affect the stomach acid. eg. PPI or H2 blockers

should avoid any antibiotics too.

stop the above for at least 2 - 4 weeks to get accurate breath test result.