The review is dedicated to the analysis of the accumulated data on the study of Helicobacter pylori (H. pylori) since the detailed description of this bacterium as the main etiological factor of gastrointestinal diseases. The work shows the dual role of H. pylori both as a bacterial pathogen for humans and as a potential representative of the normal microbiome of the stomach. In most scientific publications, the attention of researchers is focused entirely on the consideration of the pathogenic properties of H. pylori in the development of chronic gastritis, peptic ulcer disease (PUD) and gastric cancer (GC), and also considers the development of effective methods of eradication therapy. Along with this, in recent years, more and more often there are works that indicate a potentially positive effect of this bacterium on the human body and the occurrence of a number of negative consequences after eradication therapy. In this connection, the question of the probable affiliation of H. pylori to the composition of the human microbiome is discussed. Data on the high prevalence of the microorganism in the population and its asymptomatic coexistence with humans indicate the persistence of the bacterium in the body, most likely as a representative of the microbiome. The accumulated data on the effect of H. pylori on human health demonstrate a clear ambiguity of the problem. In this regard, it is important to answer the question whether it is necessary to create programs for mass eradication of H. pylori, or whether it is necessary to approach the implementation of eradication therapy in a more personalized way.