Table 1_Inflammatory, antioxidant, and gut microbiota–related dietary indices and gastric cancer risk: a case–control study.docx

Multivariable logistic regression analyses were performed to evaluate associations between dietary indices and gastric cancer risk.</p>Results<p>Patients with gastric cancer had significantly higher DII scores and significantly lower CDAI and DI-GM scores compared with controls (all p < 0.001). In fully adjusted models, participants in the highest DII tertile had substantially greater odds of gastric cancer (OR: 6.21; 95% CI: 4.39–8.79), whereas higher CDAI (OR: 0.20; 95% CI: 0.14–0.28) and DI-GM (OR: 0.25; 95% CI: 0.18–0.35) were inversely associated with disease risk (all P-trend < 0.001).

DII showed positive correlations with inflammatory and oxidative biomarkers, including CRP, TNF-α, MDA, zonulin, and NLR. However, the biomarker differences across dietary-index tertiles were generally modest. Among gastric cancer cases, DI-GM tertiles were significantly associated with zonulin concentrations.

ROC analyses demonstrated moderate discriminatory performance for DII (AUC: 0.712), CDAI (AUC: 0.688), and DI-GM (AUC: 0.631).</p>Conclusion<p>In conclusion, proinflammatory dietary patterns were associated with greater odds of gastric cancer, whereas diets rich in antioxidants or supportive of gut microbiota showed inverse associations. These associations were accompanied by differences in inflammatory, oxidative stress, intestinal permeability, and microbial metabolism related biomarkers.

However, due to the case–control design, causality cannot be inferred, and the findings should be considered associational rather than causal.</p>