Bacterial load and degree of gastric mucosal inflammation in Helicobacter pylori infection.

Helicobacter pylori induces an inflammatory immune response in the gastric mucosa. The degree of gastric mucosal inflammation and its topographic distribution are key factors in the diversity of H. pylori-related complications. Here we summarize substantial evidence reported in the literature concerning the impact of H. pylori density on gastric inflammation, the development of severe complications, and its relation to H. pylori suppression therapy. Most studies demonstrate a significant correlation between H. pylori density and the grade of acute and chronic inflammation, taking into account the limitations of each method for density assessment. Overall, high bacterial loads are associated with increased acute mucosal damage and long-term changes in the gastric mucosa. The influence of H. pylori density reduction on the improvement of gastric mucosal changes was observed in studies using 'clearance' therapies. Mucosal agents provoke a significant, but not persistent, reduction in gastritis activity. Treatments suppressing the density and virulence of H. pylori could become strategies to prevent H. pylori-associated disease in the future.