The oral microbiome: A Lesson in coexistence

• Published in: PLoS pathogens 2018-01, Vol.14 (1), p.e1006719-e1006719
• Main Authors: Sultan, Ahmed S, Kong, Eric F, Rizk, Alexandra M, Jabra-Rizk, Mary Ann
• Format: Article
• Language: English
• Subjects: Animals; Antimicrobial agents; Bacteria; Binding sites; Biology and Life Sciences; Candida albicans; Coexistence; Communities; Cytokines; Development and progression; Ecological monitoring; Ecology and Environmental Sciences; Ecosystems; Health care; Host-Parasite Interactions; Host-Pathogen Interactions; Humans; Immune system; Immunity, Mucosal; Immunology; Medicine and Health Sciences; Metabolism; Microbiomes; Microbiota; Microorganisms; Models, Immunological; Mouth - immunology; Mouth - microbiology; Mouth cancer; Oncology; Pathogenesis; Pearls; Periodontics; Porphyromonas gingivalis; Research and Analysis Methods; Staphylococcus aureus; Substrates; Virulence
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1006719

Colonization itself is a harmless state; however, the fact that, under certain conditions, some microbial residents can turn pathogenic presents a quandary for oral immunity because the question is no longer how to differentiate friend from foe but rather how to determine when a friend becomes a foe. [...]setting the “rules of engagement” by the host immune system is an exceedingly complex and dynamic task. [...]the study of microbial pathogenesis in oral disease has shifted focus from the study of single bacterial species to the study of the ecology and virulence of polymicrobial communities [5]. Interestingly, even at low levels, P. gingivalis can cause a change in the quantity and composition of the microbial flora, resulting in an inappropriate inflammatory reaction to the normal microbiota [2]. [...]studies have indicated that C. albicans can exacerbate periodontitis through enhancing P. gingivalis invasion, and an increase in C. albicans colonization has been associated with severity of periodontitis [23, 24]. Several mechanisms have been proposed to explain the colonization resistance, including stimulating the host immune response against invaders, competition for substrates and host binding sites, and generating a microenvironment that is inhibitory to potential competitors [27]. [...]colonization resistance has a significant role in the stability of established communities and is a crucial component of host defense against pathogens [27].