{
  "abstract": "Background The microbiome dysbiosis is increasingly recognized as a hallmark of cancer, including gastric cancer (GC).Methods Here we conducted a metagenome-wide association study using deep shotgun sequencing of gut and oral microbial DNA from 317 individuals across two independent cohorts, with validation in a third cohort from Harbin ( IDDF2026-ABS-0138 Figure 1. Overall characteristics of 404 stool and saliva metagenomes).Results We identified 21 oral-gut shared species enriched in the gut of GC patients compared to those with chronic gastritis (ChG), including lactic acid bacteria (LAB) such as eight Streptococcus species (notably S. anginosus) and five Lactobacillus species (IDDF2026-ABS-0138 Figure 2. Microbial species differentially abundant between GC and ChG in gut and oral). While most gut microbial markers were abundant in saliva, none were significantly enriched in the saliva of GC patients, highlighting distinct oral and gut signatures. Strain-level analysis of 87 matched saliva-stool metagenomes confirmed oral-gut transmission of Streptococcus species (IDDF2026-ABS-0138 Figure 3. Oral-gut strain level similarity for eight Streptococcus species). GC-enriched LAB formed robust co-abundance networks in oral and gut microbiomes, suggesting synergistic interactions (IDDF2026-ABS-0138 Figure 4. Co-abundance network among 14 GC-enriched oral gut shared species). Functional analysis revealed enriched lactate fermentation pathways in GC stool, aligning with LAB dominance and prior findings on gastric microbiota (IDDF2026-ABS-0138 Figure 5. Enrichment of enzymes for heterolactic fermentation in the stool microbiome of GC patients). Moreover, microbiome-based classifiers achieved high predictive accuracy (AUROC = 0.85 for stool, 0.87 for saliva, IDDF2026-ABS-0138 Figure 6. Predictive performance of gut and oral bacterial markers for GC) for GC diagnosis, highlighting translational potential.Conclusions Collectively, these findings underscore the critical role of the oral-gut microbiome axis in GC.Abstract IDDF2026-ABS-0138 Figure 1Abstract IDDF2026-ABS-0138 Figure 2Abstract IDDF2026-ABS-0138 Figure 3Abstract IDDF2026-ABS-0138 Figure 4Abstract IDDF2026-ABS-0138 Figure 5Abstract IDDF2026-ABS-0138 Figure 6",
  "authors": [
    {
      "affiliations": [
        "Shenzhen Hospital, Southern Medical University, China"
      ],
      "name": "Youwen Qin"
    },
    {
      "affiliations": [
        "Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China"
      ],
      "name": "Ya-Xuan Zhang"
    },
    {
      "affiliations": [
        "BGI Genomics, Shenzhen, China"
      ],
      "name": "Li-Ping Liu"
    },
    {
      "affiliations": [
        "Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China"
      ],
      "name": "Jing-Yuan Fang"
    },
    {
      "affiliations": [
        "Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China"
      ],
      "name": "Cheng-Bei Zhou"
    }
  ],
  "title": "IDDF2026-ABS-0138 Distinct yet coordinated oral-gut microbiome signatures in gastric cancer",
  "uid": "261332c0-e9c0-59eb-add5-6cba8786feca"
}