A complex relationship: the interaction among symbiotic microbes, invading pathogens, and their mammalian host

Symbiosis between microbes and their mammalian host is vital to maintaining homeostasis. Symbiotic microbes within the gastrointestinal tract provide an array of benefits to the host, including promotion of host immunity. A coordinated effort of the host and symbiotic microbes deters the colonization and survival of many invading pathogens. However, pathogens have devised strategies to overcome these mechanisms. Furthermore, some pathogens can hijack host hormones and bacterial autoinducers to induce virulence traits. Intra- and inter-species (bacteria/bacteria) and interkingdom (bacteria/host) communication orchestrates the complex relationship among symbiotic microbes, invading pathogens, and their mammalian host. Insight into this communication will provide a foundation for the development of targeted antimicrobial therapies.