Genomic differentiation within East Asian Helicobacter pylori

Area of Science:

• Genomics
• Microbiology
• Epidemiology

Background:

• East Asia accounts for half of gastric cancer deaths globally.
• Gastric cancer incidence varies significantly across China, Japan, and Korea.
• The population structure and genomic diversity of Helicobacter pylori in this region are not well understood.

Purpose of the Study:

• To investigate genomic differences in H. pylori populations across East Asia.
• To identify sequence polymorphisms associated with increased gastric cancer risk.
• To characterize population differentiation and geographic adaptation of H. pylori.

Main Methods:

• Phylogenetic and population genetic analyses of 381 H. pylori genomes.
• Identification and functional examination of single nucleotide polymorphisms (SNPs) with high fixation index (Fst).
• Mapping of amino acid changes onto 3D protein structures.

Main Results:

• The majority of H. pylori genomes belonged to the hspEAsia population, indicating limited recent import.
• Seven distinct subregional clusters within hspEAsia were identified, correlating with ethnicity, geography, and cancer risk.
• Subpopulation-specific genetic variations were found in genes related to drug transport, host interaction, and virulence.

Conclusions:

• H. pylori populations in East Asia are geographically differentiated, not homogeneous.
• These genetic adaptations may facilitate local host and environmental adaptation.
• Further research into these genetic variations is crucial for understanding regional gastric cancer disparities.