Oral Microbiome Signatures as Potential Biomarkers for Gastric Cancer Risk Assessment

Area of Science:

• Microbiome research
• Cancer diagnostics
• Oral health

Background:

• Gastric cancer (GC) is a significant global health concern, ranking as the fifth leading cause of cancer-related mortality.
• Investigating the oral microbiota offers a potential avenue for distinguishing between GC, premalignant gastric conditions (Pre-GC), and healthy controls.

Purpose of the Study:

• To analyze the oral microbiome's biodiversity and composition in GC, Pre-GC, and control participants.
• To identify specific oral microbial signatures that can discriminate between these groups.
• To evaluate the diagnostic potential of oral microbiome profiles for GC risk prediction.

Main Methods:

• Prospective collection of mouthwash samples from 98 participants (30 GC, 30 Pre-GC, 38 controls).
• DNA extraction, sequencing, and comprehensive analyses of oral microbiome biodiversity and composition.
• Utilized receiver operating characteristic (ROC) curves to assess the discriminative power of identified microbial signatures.

Main Results:

• Significant differences in oral microbiome beta diversity were observed between GC and control groups (p<0.02).
• 32 bacterial genera were differentially abundant in GC vs. controls, and 23 in Pre-GC vs. controls.
• Models based on key bacterial signatures accurately discriminated between GC and controls (AUC=0.880) and Pre-GC and controls (AUC=0.943).

Conclusions:

• Oral microbiome profiles in GC and Pre-GC participants are distinct from controls, though similar to each other.
• These distinct oral microbial signatures hold promise for the non-invasive prediction of gastric cancer risk.