The cross-kingdom interaction between Helicobacter pylori and Candida albicans

Abstract

Helicobacter pylori infection and transmission routes Helicobacter pylori is a gram-negative microaerophilic bacterium. The infection of H. pylori can increase the risk of gastric cancer which is the second leading cause of cancer death worldwide [1]. The World Health Organization’s International Agency for Research on Cancer (IARC) has classified H. pylori as a type I (definite) carcinogen since 1994. H. pylori infection is a global health problem. In developed countries, its infection rate is 20% to 50%, while in developing countries, the infection rate of middle-aged people has reached 80% [2]. The fecal– oral and the oral–oral routes are considered as the main transmission routes of H. pylori [3]. Nevertheless, only H. pylori genes have been detected in saliva and dental plaques, but culturable H. pylori has not been isolated yet in large quantities [4], indicating that there may be some new strategies of H. pylori to implement its transmission through oral cavity. Candida albicans, a dimorphic fungus, is one of the most common fungi in the human body [5]. It was noteworthy that C. albicans and H. pylori were abundant in certain human niches, such as the root canal necrotic pulp, stomach, duodenum, and vagina [6], suggesting that C. albicans may interact with H. pylori to promote the growth, spread, and infection of H. pylori in some nonadaptive condition, such as the oral cavity and vagina.