Gastric adenocarcinoma is the second-leading cause of cancer-related death in the world. Helicobacter pylori is a Gram-negative bacterial species that selectively colonizes gastric epithelium. The resulting chronic infection is the most significant risk factor for gastric adenocarcinoma identified so far. In the host, H. pylori interacts with microorganisms, which is likely involved in the development of gastric cancer. To identify H. pylori-associated bacteria and explore the contributions of these inter-bacterial events in the process of gastric cancer, we examined the interactions of H. pylori with other microbes in the microbiota community that are implicated in the development and progression of gastric cancer. A better understanding of the complex interactions between H. pylori and altered microbiota is critical to develop personalized therapies and approaches.