Alterations of gastric fluid microbiota in patients with gastric cancer

Background: Gastric cancer (GC) remains one of the most common malignancies worldwide, highlighting the importance of characterizing microbial alterations associated with its development. Methods: This study analyzed changes in the gastric fluid microbiota of patients with GC and identified GC-related microbial signatures. Thirty patients with GC and 25 healthy volunteers undergoing routine physical examinations were included. Gastric fluid samples were subjected to absolute quantitative 16S ribosomal RNA (rRNA) gene sequencing. Differences in the microbial composition between groups were assessed using the linear discriminant analysis effect size (LEfSe). Results: The analysis revealed no significant differences in microbial diversity or richness between GC patients and healthy controls. However, the relative abundances of Neisseria and Haemophilus genera were markedly reduced in patients with GC, whereas Clostridiales bacterium canine oral taxon 162 and Prevotella 1 were increased. LEfSe identified 13 bacterial genera with linear discriminant analysis (LDA) scores ≥2.0 that discriminated between the cancer and healthy groups. Conclusions: The development of GC may be associated with alterations in the community structure of gastric fluid microbiota rather than changes in microbial diversity. LEfSe identified 13 bacterial genera with LDA scores≥2.0, which could effectively distinguish patients with GC and healthy controls.