The microbiota: intricately linked to diagnosis and treatment of gastric cancer

While Helicobacter pylori remains a well-established driver of gastric cancer, recent research has shifted to spotlight the wider gut microbiome. Changes in the composition of these non- Helicobacter pylori microbes-and the metabolites they produce-are now closely linked to clinical markers of gastric cancer. This connection not only deepens our understanding of the disease but also opens new avenues for diagnostic and prognostic biomarkers. The modulation of gut microbiota has moved into the therapeutic spotlight for gastric cancer. We now understand that these microbial communities shape surgical recovery, influence the effectiveness of immunotherapy and chemotherapy, and can alter treatment-related side effects. Such mechanistic insights are paving the way for more precise therapeutic strategies. This review consolidates contemporary evidence on the role of microbiota in the development, diagnosis, prognosis, and treatment of gastric cancer. It places particular focus on emerging biomarkers and translational applications, concluding with identified gaps and proposed directions for future research.