Comparison of the Microbiome Diversity in Gastric Cancer Patients and in Non-Cancerous Patients

Aims Gastric cancer is the most common cancer in Korea. The most clearly known microbiologic factor is Helocibacter pylori and it is the leading cause of gastric cancer. According to studies, H.pylori is rarely detected in atrophic mucosa. This suggests that hypochlorhydric condition created by H.pylori may provide suitable environment for carcinogenesis. This raises a question about possibility that bacteria other than H.pylori could contribute to carcinogenesis of gastric cancer. Based on the hypothesis that certain microbiome may accelerate carcinogenesis, we intend to observe the differences in the distribution of microbiomes in gastric cancer patients and normal patients.

Methods Gastric mucosa collected from seven patients with advanced gastric cancer and six healthy individuals. Tissues were obtained from the cancer lesions in cancer group. In control group, biopsies were performed from antrum. DNA was extracted and 16s rRNA genes were amplified from the isolated DNA. They were analyzed by using terminal restriction fragment length polymorphism. Cloning and sequencing of 16S rRNA genes were performed.

Results Higher number of species was detected in control group, average of 102 species, compared to the cancer group, average of 72 species. The gastric cancer microbiome was characterized by reduced microbial diversity. Various bacterial species were found in both groups but distribution was quite different. Fusobacteria was more dominant in cancer group and Rhodoacterales was found more prominent in control group. The gastric H.pylori was detected only in one patient from each group.

Conclusions More diverse gastric microbiome was observed in non-cancerous patients and composition of species was different between the two groups. These results suggest that microbial dysbiosis may contribute to gastric carcinogenesis, but it is not yet clear whether microbial transition accelerates carcinogenesis. Further studies should include analysis of spatial and temporal composition of gastric microbiome. Better understanding of microbial differences could verify the principles of carcinogenesis.

Citation: Bang EJ, Keum B, Kim S et al. eP73 COMPARISON OF THE MICROBIOME DIVERSITY IN GASTRIC CANCER PATIENTS AND IN NON-CANCEROUS PATIENTS. Endoscopy 2021; 53: S120.

Publication History

Article published online:
19 March 2021