Higher Motility Enhances Bacterial Density and Inflammatory Response in Dyspeptic Patients Infected with Helicobacter pylori

Background: Motility mediated by the flagella of Helicobacter pylori is important for the cells to move toward the gastric mucus in niches adjacent to the epithelium; then, H. pylori uses the adhesin SabA to interact with sialyl-Le^x on inflammatory host cells for persistent infection. Here, we reveal the clinical association of bacterial motility, SabA expression, and pathological outcomes. Methods: Ninety-six clinical isolates were screened for bacterial motility, and the expression of SabA of each isolate was confirmed by Western blotting. H. pylori-infected patients were assessed for their bacterial density, sialyl-Le^x expression, inflammatory scores, and clinical diseases. Results: The mean diameter in the motility assay was 17 mm, and eight (8.3%) of the strains had impaired motility, with a diameter <5 mm. H. pylori density in cardia, the acute inflammatory score in the body locus, and the prevalence rate of gastric atrophy were increased in patients infected with higher-motility strains (p = .023, <.001, or <.001, respectively). The total inflammatory scores (both acute and chronic) and bacterial density dramatically increased in patients expressing the sialyl-Le^x antigen and infected with higher-motility, SabA-positive H. pylori (p = .016, .01, or .005, respectively). Conclusion: These results suggest that the higher motility of H. pylori enhances pathological outcomes, and the SabA-sialyl-Le^x interaction has a synergistic effect on virulence of the higher-motility strains.