What is the Relevance of Gastric Microbiota Beyond H. pylori?

The role of Helicobacter pylori as key factor in gastric inflammation and the development of (pre-)cancerous lesions is undisputable. As an open system, the human upper gastrointestinal tract harbors a complex bacterial community which is highly impacted by the absence or presence of H. pylori. The interaction between other bacteria and H. pylori might impact on gastric carcinogenesis.

Several studies demonstrated differences in the composition of the gastric bacterial community in different stages of gastritis and between samples from tumor and adjacent tissue. In addition, animal studies demonstrated an increased and accelerated development of precancerous lesions in mice colonized with intestinal flora and H. pylori compared with mice mono-infected with H. pylori.

Other bacteria beyond H. pylori enter the focus in research on gastric carcinogenesis. However, we are still far from a thorough understanding of the pathophysiology of host-microbiota interaction and its impact on the development of malignant and precancerous changes.