The Effect of 6-Week Advanced Oral Care on Oral Microbiome and Mycobiome Composition in People With Dementia Living in Residential Aged Care

Abstract

Objectives

Oral health is an important aspect of quality of life for older people, especially those with dementia. The impact of an active oral hygiene program on the oral microbiome was explored in a group of older participants (average age 84 years old) with dementia against a separate control group whose oral hygiene followed the status quo.

Materials and Methods

The oral cavity bacteriomes and mycobiomes were assessed from swabs of cheek, gum, and tongue surfaces. Samples were collected at the beginning and end of a 6-week study period, and bacterial and fungal community profiles were determined by short-read metabarcode sequencing of 16S and 18S ribosomal RNA (rRNA) genes, respectively.

Results

The predominant bacteria were found to be in order of abundance: Streptococcus, Cellulosimicrobium, Rothia, Veillonella, Prevotella, Actinomyces, and species that belonged to the families Lactobacillaceae and Gemellaceae. Similarly, common fungal species belonged to Saccharomyces and the Candida-Lodderomyces clade. The intensive oral hygiene program did not affect bacterial or fungal taxa distributions. A minor reduction in bacterial species richness (15%–20%) was observed post-intervention in both groups. Mycobiome outcomes varied by sampling sites, unlike bacterial communities, which were relatively homogenous. Participant differences, potentially individual health status, genetics, and other personal factors, explained most data set variations (70%–78% of the variance), with the experimental design accounting for about 2%.

Conclusions

To enable an alteration of oral cavity communities that may improve overall oral health and mitigate infectious disease risks in older people, especially those in residential care, targeted and specific hygiene approaches may be needed for the purposes of assessing effectiveness at the microbiological level. Future research should focus on developing and testing such targeted strategies to mitigate infectious disease risks and enhance the quality of life for older individuals, particularly those in residential care settings.