A Pilot Study Assessing the Oral Microbiome in Women of Menopausal Age: Do Oral Nitrate–Reducing Bacteria Play a Role?

Introduction
The links between oral health and female ageing are poorly understood, but many changes occur in the oral cavity of menopausal women that affect quality of life, and few current oral health interventions consider gender as part of their approach. The aim of this pilot study was to test the hypothesis that the oral microbiome and microenvironment change during female ageing and are thus worthy of further consideration both experimentally and clinically.
Methods
This observational pilot study retrospectively assessed women aged 18 to 89 years (n = 60) attending a UK primary care dental school facility for blood pressure screening, further analysing the salivary oral microbiome using metagenomics and the biochemical microenvironment using high-performance liquid chromatography. Periodontal health screening (Basic Periodontal Examination [BPE]) was then conducted as part of routine clinical care.
Results
The cross-sectional design classified women into <32 years (n = 18), 40 to 49 years (n = 10), 50 to 59 years (n = 20), and 60+ years (n = 12), but the differences in salivary oestradiol levels between groups were inconclusive. Small numbers were not enough to detect differences in oral microbiome abundance, but nitrate-reducing species (P < .05), nitrate-nitrite–reducing activity (P < .05), and buffering capacity all increased as women aged 60+ years (P < .01), warranting increased numbers. Ageing women also had higher blood pressure (P > .05), were more likely to have periodontal pockets >5.5 mm (BPE4), and had an increased abundance of Porphyromonas (P < .05), but a full periodontal assessment is needed.
Conclusions
These observations suggest that the composition of the oral microbiome changes as women age, and thus, prospective and longitudinal oral microbiome studies with larger numbers are needed, including concurrent full periodontal assessment, plasma hormonal levels, and salivary flow. However, this study suggests that the oral microbiome in older women may require special consideration, with an increased focus on tailored oral hygiene interventions for this group.