Microbiological changes of the ageing oral cavity

Ageing is a physiological process that affects virtually all systems of the human body. Age-associated changes in the oral cavity reflect changes in the composition of its microbial inhabitants, which can be compatible with health or form dysbiotic communities that favor the establishment of disease. This paper focuses on discussing such age-driven changes of the oral microbiome, as well as their association with common oral infectious diseases, including dental caries, periodontitis, peri-implantitis and oral candidiasis. This is a comprehensive narrative review of the literature. The oropharyngeal microbiome of elderly individuals may foster a number of microorganisms such as enterobacteria, pseudomonads, staphylococci and yeasts that can become opportunistic pathogens in elderly individuals with weakened immunity or deteriorated general health. No considerable microbiological variations are noted with regards to common oral diseases, such as dental caries and periodontitis, between younger and elderly populations, whereas an increase in the prevalence of oral actinomycetes is noted by ageing. Whether naturally occurring or driven by underlying disease, the ecology of oral cavity is dynamically modified over time, eliciting changes in the composition of the resident oral microbiome.