Gastric Cancer Microbiome.

Area of Science:

• Microbiome research
• Gastric carcinogenesis
• Metagenomic analysis

Background:

• Gastric cancer (GC) microbiome patterns are debated due to population, clinical, and methodological variations.
• Helicobacter pylori is key in early gastric carcinogenesis, but non-H. pylori microbes also play roles in later stages.
• Reproducibility issues and contamination hinder consistent interpretation of metagenomic data in GC studies.

Purpose of the Study:

• To minimize bias and limitations in existing GC microbiome research.
• To conduct a comprehensive analysis of publicly available metagenomic data across various gastric carcinogenesis conditions.
• To provide a reliable interpretation by analyzing a large, diverse sample set under a standardized protocol.

Main Methods:

• Comprehensive analysis of publicly available metagenomic data.
• Inclusion of samples from various conditions: chronic gastritis (CG), gastric cancer (GC), adjacent (ADJ) tissues, and healthy controls (HC).
• Standardized bioinformatics protocol applied to a large, aggregated dataset to overcome small sample size and standardization issues.

Main Results:

• Helicobacter and Prevotella were among the top 6 genera across all groups.
• Helicobacter dominated in CG, GC, and ADJ groups, while Prevotella was most abundant in HC samples.
• Distinct bacterial group abundances and diverging metabolic pathways were observed across the carcinogenesis cascade.

Conclusions:

• The study identified significant shifts in gastric microbiome composition and function during carcinogenesis.
• Findings highlight the differential roles of bacterial genera like Helicobacter and Prevotella in health and disease.
• This microbiome data may inform future interventions to prevent gastric carcinogenesis or reduce GC risk.