H. pylori Infection: The Leading Cause of Gastritis and Peptic Ulcers

A Bacterium That Thrives in Acid

Helicobacter pylori is a spiral-shaped, flagellated bacterium that uniquely colonizes the human gastric mucosa. It survives the stomach's acidity by producing urease, which neutralizes acid in its immediate microenvironment. Its presence triggers a cascade of inflammation and tissue damage.

Conditions Caused by H. pylori

• Chronic gastritis: Persistent inflammation of the stomach lining; nearly universal in infected individuals.
• Peptic ulcers: Gastric (stomach) or duodenal ulcers; H. pylori causes >90% of duodenal and 70–90% of gastric ulcers.
• Gastric cancer & MALT lymphoma: Long-term infection is a WHO Class I carcinogen; eradication reduces cancer risk.

Diagnosis: Non-Invasive vs. Invasive

• Non-invasive (preferred for initial testing): Urea breath test (high accuracy), stool antigen test.
• Invasive (requires endoscopy): Rapid urease test (CLO test), histology, culture (allows antibiotic sensitivity testing).

Treatment Regimens

Antibiotic resistance varies by region, guiding regimen choice:

• Standard triple therapy (14 days): PPI + clarithromycin + amoxicillin (or metronidazole).
• Concomitant or quadruple therapy: Preferred in areas with high clarithromycin resistance (>15–20%). Includes PPI, bismuth, tetracycline, and metronidazole.
• Confirm eradication: Retest with urea breath test or stool antigen ≥4 weeks after completing antibiotics (and ≥1 week off PPIs).