Helicobacter pylori in Russian children: a multidimensional cross-sectional study

Given that Helicobacter pylori infection typically remains asymptomatic in children and only a limited number of cases progress to clinically significant disease, comprehensive investigation of infection features is essential for risk prediction and stratification. This cross-sectional study integrates clinical, epidemiological, microbial, and molecular approaches to investigate pediatric H. pylori infection in Northwestern Russia, focusing on regional prevalence, diagnostic accuracy, antimicrobial resistance, virulence profiling, and gastric microbiota composition. Among 492 asymptomatic children, the overall H. pylori seroprevalence was 15.4%, which is significantly lower than that reported during 1995–2011. Biopsy-based analysis of 70 symptomatic, treatment-naïve children who underwent esophagogastroduodenoscopy revealed H. pylori in 72.9% of samples by PCR, compared to 30.0% by histology ( p < 0.0001), with an overall concordance of 51.4% between the methods. Among 11 cultured H. pylori isolates, antimicrobial resistance rates were 9.1% for clarithromycin and levofloxacin, and 36.4% for metronidazole. The high-virulence genotype ( cagA / vacA s1m1i1/ oipA ) was observed in a patient with erosive-ulcerative pangastritis. 16S rRNA sequencing revealed distinct alterations in gastric microbiota composition associated with H. pylori status. Together, these findings suggest that PCR offers a significantly higher detection rate than histology and may serve as a valuable adjunctive diagnostic tool in pediatric patients. The preliminary resistance data caution against empiric metronidazole-based therapy, while the observed microbiota alterations warrant further investigation. Larger studies are needed to validate these findings and guide pediatric treatment strategies for the region.