Is hyperacidity related to H. pylori infection?

Relationship Between Hyperacidity and H. pylori Infection

H. pylori infection typically causes hypoacidity rather than hyperacidity in most cases, though in some patients with duodenal ulcers, it may paradoxically increase acid secretion.

Pathophysiological Mechanisms

H. pylori affects gastric acid secretion differently depending on the pattern and location of infection:

• Antrum-predominant gastritis:

  • Increases gastrin release from G cells 1
  • Decreases somatostatin expression 1
  • Results in increased acid secretion
  • Associated with duodenal ulcers

• Corpus-predominant gastritis:

  • Inhibits parietal cell function
  • Promotes gastric atrophy
  • Results in decreased acid secretion (hypochlorhydria)
  • Associated with increased gastric cancer risk 1

Distribution of Infection and Acid Secretion

The relationship between H. pylori and acid secretion depends on the distribution of infection in the stomach:

• In individuals with high baseline acid secretion, H. pylori colonization tends to be limited to the antrum, potentially leading to even higher acid output 2
• In those with lower baseline acid secretion, H. pylori more easily colonizes the corpus, leading to corpus-predominant gastritis and further reduction in acid production 2

Clinical Implications

The Asia-Pacific consensus on GERD management notes important relationships between H. pylori and acid-related disorders:

• H. pylori eradication may actually trigger reflux esophagitis in some patients (6% annual incidence after eradication) 3
• Male gender and large waist circumference are risk factors for developing esophagitis after H. pylori treatment 3
• Japanese patients who developed reflux esophagitis after H. pylori eradication had a greater prevalence of hiatus hernia and more severe corpus gastritis 3

Diagnostic Considerations

When evaluating patients with suspected hyperacidity:

• Consider testing for H. pylori in patients with persistent symptoms despite 4 weeks of PPI therapy 4
• Recognize that H. pylori infection may cause dyspeptic symptoms through various mechanisms, including effects on gastrin homeostasis and acid secretion 5
• Idiopathic gastric acid hypersecretion (basal acid output >10 mmol/h with normal gastrin levels) should be considered in patients with refractory acid-peptic disorders 6

Management Approach

For patients with suspected hyperacidity:

1. Test for H. pylori if symptoms persist despite standard therapy
2. If H. pylori positive:
   • Consider eradication therapy, recognizing that this may not resolve all dyspeptic symptoms 3
   • Monitor for potential development of reflux symptoms after eradication
3. If hyperacidity persists:
   • Consider PPI therapy optimization (timing, dose, type) 3
   • For refractory cases, consider higher-dose PPI or alternative approaches 6

Conclusion

The relationship between H. pylori and gastric acid secretion is complex and bidirectional. While H. pylori typically causes hypoacidity through corpus gastritis and atrophy, in some patients—particularly those with antrum-predominant infection—it may paradoxically increase acid secretion. Understanding this relationship is crucial for appropriate management of acid-related disorders.