Helicobacter pylori: Symptoms, Diagnosis, and Treatment of Infection

Helicobacter pylori is a spiral-shaped Gram-negative bacterium, one of the few able to survive in the stomach's highly acidic environment thanks to its production of urease, which locally neutralizes hydrochloric acid. Infection usually occurs in childhood, via the fecal-oral or oral-oral route, and without treatment can persist for decades, even a lifetime.

A key, often overlooked fact: in most infected people, H. pylori never causes any symptoms at all. The bacterium can silently colonize the stomach for decades. This makes the question "is it worth looking for and treating infection in an asymptomatic person" considerably more complex than it might seem — and we return to it later in the article.

H. pylori is the main cause of gastric and duodenal ulcer disease — it triggers chronic inflammation of the stomach lining, which in some infected people leads to the formation of defects. A far more serious, though rarer, consequence is the link to gastric cancer: the World Health Organization classifies H. pylori as a class I carcinogen, and chronic infection is the strongest known risk factor for this cancer.

For decades, the standard treatment was triple therapy: a proton pump inhibitor combined with two antibiotics, most often clarithromycin and amoxicillin, for 7-14 days. The problem is that this therapy's effectiveness has been systematically declining as bacterial resistance to clarithromycin rises — in many regions of the world it has already crossed the threshold at which triple therapy stops being a reliable first-line choice.

In practice, this means a physician deciding on a treatment regimen should factor in local antibiotic resistance data rather than automatically reaching for a decade-old regimen. Bismuth quadruple therapy usually lasts 10-14 days and comes with a somewhat higher number of side effects (including black stool discoloration from bismuth preparations, which is harmless but can be alarming to patients), but achieves higher eradication success under conditions of rising resistance.

Meta-analyses of newer studies show that standard triple therapy's effectiveness in intention-to-treat analysis now averages around 74%, while quadruple therapy reaches about 82-83%. In other words: even with appropriately chosen treatment, the first eradication attempt fails in some patients, requiring second-line treatment, ideally selected based on antibiotic susceptibility testing where available.

H. pylori is a rare example of a situation where eradicating a single bacterial pathogen has a documented, though population-dependent, impact on the risk of a specific cancer — a solid argument for diagnosis in people with justified indications. At the same time, rising antibiotic resistance means "just in case" treatment, without considering local resistance data, increasingly ends in failed eradication and unnecessary antibiotic exposure.

A sensible approach is targeted diagnosis of people with genuine indications — symptoms, a history of peptic ulcer disease, unexplained anemia, or family history — treatment consistent with current guidelines that account for local resistance, and mandatory confirmation of eradication with a follow-up test after completing therapy.