Reagent for detecting streptococcus constellatus and clinical application thereof

The invention relates to the technical field of clinical diagnosis of gastric cancer, and discloses a reagent for detecting streptococcus constellatus. The reagent comprises a biomarker and an internal reference primer, wherein the biomarker comprises a specific primer A and a specific primer B special for streptococcus constellatus. The invention also discloses clinical application of the reagentto diagnosis of gastric cancer, especially early gastric cancer. The reagent and the clinical application detection method provided by the invention can realize diagnosis screening of gastric cancer,especially early gastric cancer for the high-risk population by analyzing the relative abundance of digestive tract excretion or secretion, such as streptococcus constellatus in feces or saliva. Thereagent is a non-invasive, simple, accurate, sensitive and highly-accepted novel detection means, is expected to be an auxiliary diagnosis means for early diagnosis of gastric cancer, and will help the high-risk population to d