Differences in oral microbiota between elderly and adults: A systematic review

Area of Science:

• Microbiology
• Gerontology
• Oral Health

Background:

• The aging process can significantly alter the oral microbiome's diversity and composition.
• Changes in the oral microbiome may impact overall systemic health.
• Understanding these shifts is crucial for maintaining healthspan and quality of life in the elderly.

Purpose of the Study:

• To systematically review and compare the oral microbiota of elderly individuals (≥60 years) with that of younger adults.
• To identify consistent changes in oral microbial composition associated with aging.

Main Methods:

• A comprehensive literature search was conducted across major databases (PubMed, Medline, EMBASE, CINAHL) for studies published between 2005 and May 2023.
• Included studies compared oral microbiomes of elderly and younger adults using 16S rRNA sequencing.
• Ten studies met the inclusion criteria after risk of bias assessment.

Main Results:

• Results on overall microbial diversity (alpha and beta) and phyla abundance showed significant inconsistencies across studies.
• A consistent decline in the abundance of Haemophilus, Granulicatella, and Veillonella was observed in elderly populations.
• An increase in the abundance of Comamonas was noted in elderly individuals across multiple studies.

Conclusions:

• Variability in findings suggests confounding factors like oral hygiene, systemic health, medications, and lifestyle influence the aging oral microbiome.
• Longitudinal study designs and standardized methodologies are essential for future research.
• Further investigation is needed to clarify the roles of specific genera (e.g., Haemophilus, Comamonas) in elderly oral health and stability.