Human oral microbiome in aging: A systematic review

Abstract

Studying aging and risk factors associated with chronic non-communicable diseases is increasingly relevant due to the progressive aging of the global population. Risk factors have focused on diet, physical exercise, cognitive activity, and lifestyle habits; however, recent research has begun to explore how the oral microbiome may influence health and contribute to chronic diseases. The aim of our systematic review is to evaluate the link between human oral microbiome and aging. This SR was carried out using PubMed, Cochrane Library, and Embase, identifying 3490 records, of which 6 met our inclusion/exclusion criteria. These studies were qualitatively assessed using the Revised Risk of Bias Assessment Tool for Nonrandomized Studies of Interventions. Overall, the evidence suggests that while the bacterial and fungal communities remain similar across age groups, there is an increased presence of periodontal pathogens in older subjects. Moreover, bacterial species richness and alpha-diversity decrease with advancing age, though no clear age clustering was observed. Although the reviewed studies offer insights into the association between aging and changes in the oral microbiome, further research is required to address confounding factors, limitations in sample size, and gender differences, in order to better elucidate the role of microbiome alterations in general health.

Keywords: Aging; Microbiome; Relative taxa abundance chronic non- communicable diseases; Saliva oral; Systematic review; α; β -diversity.