A bug most people are surprised to hear about
Long after antibiotics revolutionized medicine, one persistent bug still affects roughly half the world's population: Helicobacter pylori. It quietly lives in the stomach, often without symptoms. But for some people, it triggers ulcers, chronic stomach inflammation, and a higher risk of stomach cancer.
A new mega-review of treatment regimens shows how well — and how unevenly — modern antibiotics still handle it.
H. pylori has been blamed for the majority of stomach ulcers since the 1980s, when researchers first connected the dots. Treatment has been a triple- or quadruple-drug cocktail of acid blockers and antibiotics, taken for one to two weeks.
For a long time, those cocktails cured almost everyone. Today, that's no longer always true. Resistance to several of the antibiotics in the mix has been climbing, and patients in some regions now face cure rates well below the historic 90% goal.
The old way versus the new way
For years, doctors followed standardized regimens that worked nearly everywhere. The differences between hospitals and countries were small.
Now they aren't. Resistance patterns vary by region. A regimen that cures 90% of patients in one country may cure only 70% in another. Tailoring treatment to local resistance — or even to a patient's individual bacterial test — has become a serious topic of debate.
This new meta-analysis tries to make sense of the patchy picture by combining as many studies as possible.
How the bug resists treatment
Imagine a sports team learning to defeat a coach's standard play. The first few seasons, the play works. The team tries it again and again. Over time, opposing teams figure out how to block it.
That's what's happening with antibiotics for H. pylori. The bacteria have many ways to evolve resistance — pumps that push antibiotics back out of the cell, slight changes in the drug target inside the cell, and others. With each round of widespread use, more strains carry these tricks.
The standard cocktail still wins most matches, but no longer in a clean sweep.
The study snapshot
Researchers searched major databases through October 2025 for randomized and observational studies that reported eradication rates or side effects. Fifty-seven studies covering nearly 20,000 patients across 127 different treatment arms were pooled. The team used random-effects models to estimate cure rates while accounting for the wide differences between studies.
The overall pooled cure rate was about 83%. That's solid but below the historical target of 90% — a benchmark seen as the cutoff between a generally reliable treatment and one that needs to be reconsidered.
Cure rates varied widely between studies, by region, by drug combination, and by treatment duration. Newer regimens — those designed in the past few years to handle higher resistance — tended to do better than older ones.
The team also flagged signs of publication bias, meaning more positive studies may have made it to print than negative ones. That suggests the real-world success rate could be slightly lower than the pooled number suggests.
This doesn't mean H. pylori treatment doesn't work. It means the first attempt fails more often than it used to.
Where this fits in the bigger picture
H. pylori treatment is a test case for the broader battle against antimicrobial resistance. The bug has had decades of widespread antibiotic exposure, and its resistance patterns mirror what's happening with many other bacteria.
If treatment recommendations don't keep pace with rising resistance, eradication rates will keep slipping. Some countries are now requiring testing for resistance before treatment is started, especially for patients who've failed a first round.
If you've been told you have H. pylori and are starting treatment, the practical takeaways are these. Take every dose of every drug exactly as prescribed for the full duration. Missing pills is one of the biggest reasons treatment fails. Plan your dosing schedule and stick to it.
After treatment, follow-up testing — usually a stool antigen test or breath test about a month after finishing — can confirm whether the bug is gone. If it isn't, your doctor can switch to a different regimen.
If you've already failed one round of treatment, don't assume the same drugs will work again. Ask whether resistance testing is available at your clinic.
The included studies vary widely in design, location, and patient populations. Combining them mathematically gives an overall picture but blurs important regional differences. The signs of publication bias mean the true cure rate may be slightly lower than 83%. And the rapid pace of resistance evolution means even today's numbers will shift over the next few years.
Several new approaches are being tested, including completely new antibiotic combinations, longer treatment courses, and personalized regimens guided by stool DNA testing. A vaccine for H. pylori has been in research for years and remains a long-term goal. In the meantime, careful prescribing and good patient adherence are the best tools available.
