The Oral-Gastric Microbial Axis in Gastric Cancer: Mechanisms Underlying Development and Progression

Area of Science:

• Microbiome research
• Gastrointestinal oncology
• Oral-gastric microbial axis

Background:

• Gastric cancer (GC) etiology is shifting from Helicobacter pylori to a polymicrobial oral-gastric axis.
• Ectopic colonization by oral pathobionts contributes to mucosal dysbiosis and GC development.
• The tumor microenvironment is remodeled by biofilms, metabolic reprogramming, and immune dysregulation.

Purpose of the Study:

• To examine the mechanisms of oral pathobiont colonization and their role in gastric cancer.
• To analyze functional modules like biofilm formation, metabolic reprogramming, and immune dysregulation in GC.
• To review diagnostic and therapeutic strategies for gastric cancer based on microbiome research.

Main Methods:

• Review of current literature on the oral-gastric microbial axis in gastric cancer.
• Analysis of mechanisms including pathobiont colonization, dysbiosis, and tumor microenvironment remodeling.
• Evaluation of diagnostic biomarkers, artificial intelligence applications, and therapeutic strategies.

Main Results:

• The oral-gastric axis, beyond H. pylori, plays a significant role in GC etiology.
• Genotoxic metabolites and chronic inflammation promote carcinogenesis.
• Noninvasive biomarkers and AI integration offer transformative potential for early GC detection.
• Microbiome composition influences the efficacy of immunotherapy and chemotherapy.

Conclusions:

• Restoring microbial homeostasis presents a promising strategy for GC prevention and treatment.
• Translating microbiome research into personalized clinical practice is crucial for gastrointestinal malignancies.
• A comprehensive understanding of the oral-gastric microbiome is essential for advancing GC management.