Helicobacter pylori infection is associated with the co-occurrence of bacteria in the oral cavity and the gastric mucosa.

Background: Pathogens capable of impacting gastrointestinal tract tumor development are located in the oral cavity, but whether these oral bacteria are able to colonize the gastric mucosa in gastric cancer (GC) patients and whether Helicobacter pylori infection can influence this process remains to be established.

Methods: Microbial 16S rDNA deep sequencing was conducted to characterize bacteria present in paired gastric mucosa and tongue coating samples in 27 patients with superficial gastritis (SG) and 11 GC patients.

Results: While the overall composition of the gastric mucosa and tongue coating microbiomes differed substantially, certain bacteria were present in both of these communities.

A Comparison of Tumor-Associated and Non-Tumor-Associated Gastric Microbiota in Gastric Cancer Patients.

Background: How gastric cancer (GC) incidence is associated with changes in the gastric microbiome has not been firmly established. The present study therefore aims to investigate the microbial communities present within the gastric mucosa of patients with superficial gastritis (SG) or GC.

Methods: Paired tumor and paracancerous samples of the gastric mucosa were collected from 18 patients being surgically treated for GC and from 32 patients with SG being treated via gastroscopy.

Relationship between serum inflammatory cytokines and lifestyle factors in gastric cancer.

Chronic inflammation is associated with increased risk of gastric cancer (GC), and GC risk is significantly associated with lifestyle. The aim of the present study was to explore the association between serum inflammatory cytokines and lifestyle factors in GC. A total of 20 serum inflammatory cytokines were measured in a hospital-based case-control population with 142 GC patients and 98 healthy controls.