in the Oral Cavity: Current Evidence and Potential Survival Strategies.

() is transmitted primarily through the oral-oral route and fecal-oral route. The oral cavity had therefore been hypothesized as an extragastric reservoir of , owing to the presence of DNA and particular antigens in distinct niches of the oral cavity. This bacterium in the oral cavity may contribute to the progression of periodontitis and is associated with a variety of oral diseases, gastric eradication failure, and reinfection. However, the conditions in the oral cavity do not appear to be ideal for survival, and little is known about its biological function in the oral cavity. It is critical to clarify the survival strategies of to better comprehend the role and function of this bacterium in the oral cavity. In this review, we attempt to analyze the evidence indicating the existence of living oral , as well as potential survival strategies, including the formation of a favorable microenvironment, the interaction between and oral microorganisms, and the transition to a non-growing state. Further research on oral is necessary to develop improved therapies for the prevention and treatment of infection.