Can a gastroscopy detect Helicobacter pylori? Helicobacter pylori is a type of bacteria, thus it cannot be seen with the naked eye. However, recent research shows that Helicobacter pylori is closely related to certain mucosal appearances observed under endoscopy. Therefore, endoscopists can infer the infection of Helicobacter pylori based on certain mucosal appearances. However, if a patient is just testing for Helicobacter pylori infection, there is no need for a gastroscopy. We can choose some non-invasive methods such as the carbon-13 breath test, carbon-14 breath test, stool antigen test, and serological antibody test, which are commonly used detection methods. Moreover, after treatment for Helicobacter pylori, it is recommended to choose the carbon-13 or carbon-14 breath test, as they are quite accurate.