In a recent pilot study, UK researchers reported age-associated changes in nitrate-reducing activity, salivary buffering capacity and periodontal risk markers—alongside higher blood pressure—highlighting a need for larger, hormone-verified studies.
“If this menopausal/hormonal link was proven with more in vivo research, it suggests that women may require personalized care pathways for rebalancing the oral microbiome and restoring oral health,” they wrote in the International Dental Journal.
The research was supported by Oralieve, a British oral care brand that offers a range of products designed to relieve dry mouth by mimicking the natural enzyme system found in saliva—complemented by match-funding from Enterprise Solutions at the University of Plymouth in the UK.
The aging oral microbiome and its detriments
The researchers noted that menopause and reproductive aging remain under-mapped in oral health research and care and that it is important to understand the impact of changes in the oral microbiome over time that may affect cardiovascular health.
“Assumed to result from hormonal changes, many women in the menopausal and perimenopausal age groups report a change from their previously experienced oral physiology, with symptoms such as dry mouth, burning mouth syndrome and taste disturbances developing, which can have a considerable impact on quality of life,” they wrote.
Of particular interest within the oral microbiome are the nitrate-reducing oral bacteria that support the nitrate–nitrite–nitric oxide pathway, which is implicated in vascular function and blood pressure regulation, raising questions about how oral ecology and systemic health may intersect as women age.
Here, the researchers cite Veillonella, Rothia, Neisseria, Actinomyces bacteria and, to a lesser extent, Prevotella genera as participants in a healthy oral microbiome.
“Such oral nitrate–reducing bacteria (ONRB) facilitate the conversion of dietary nitrate into nitrite, which, once ingested, can form NO that dilates blood vessels to lower blood pressure through homeostatic mechanisms,” they wrote. “Interestingly, Prevotella copri increases in abundance and Veillonella tobetsuensis decreases after menopause, but the abundance and activity of all nitrate-reducing species remain underexplored in women as they age.”
Study details
The observational pilot study analyzed samples from 60 women between the ages of 18 and 89, who were classified into aging groups ranging from 30-and-under to 60-and-over who were then assigned a menopausal group determined by age. Measurements included blood pressure screening, salivary oral microbiome analysis and results of a basic periodontal examination.
While the researchers found no clear, across-the-board shift in overall oral microbiome diversity between age groups or across menopause stages, they did observe that two bacteria closely tied to inflammatory gum disease, Porphyromonas gingivalis and Tannerella forsythia, became more common with increasing age and advancing menopausal status.
Commenting on the study findings, John Hale, PhD, chief technology officer at New Zealand-based oral probiotic company Blis Technologies noted as concerning the increase in periodontal pocket depth and of key red complex bacteria (Porphyromonas gingivalis and Tannerella forsythia)—both markers of periodontal disease and suggesting that menopausal aging may trigger an imbalance due to estrogen declines.
“There is an established connection between periodontal health and systemic health issues such as increased cardiovascular and Alzheimer’s diseases,” he said. “I think this study is yet another great example of the key importance of the balance in our oral microbiomes for not only our local oral health but also the impact it has on our systemic health.”
The UK researchers reported that blood pressure tended to rise with age and later menopause stages, in line with the higher heart and blood-vessel risks seen during this life stage. Hormone readings in saliva between age bands were inconclusive, but nitrate-related activity—part of a biochemical pathway linked to nitric oxide—was highest in older participants, a pattern the authors speculated could represent a compensatory response.
Findings also indicated that salivary buffering capacity increased with female aging and menopausal progression, potentially enhancing acid neutralization but not necessarily combating pathogenic bacteria. The study noted that this also presented a paradox in need of clarification since buffering capacity is typically associated with increased salivary flow yet menopause is commonly linked to dry mouth.
“These findings point to a complex, nonlinear relationship between age, hormone status and microbial function, with implications for designing targeted interventions to modulate the oral microbiome that could also improve both oral and cardiovascular health,” the researchers wrote. “Findings also reinforce that oral and dental research should be conducted in both women and men, with awareness of the differences, as different hormonal factors are at play.”
They added that to date, probiotic studies during menopause have focused on the gut and vaginal microbiome but have thus far neglected the mouth.
More research needed
While the preliminary results support more menopause-aware oral health research, the researchers emphasized that larger studies are needed to confirm how much of the shift is due to hormones versus aging itself.
Dr. Hale noted that comprehensive assessments—such as oral microbiome analysis, professional dental evaluations and blood hormone measurements—would strengthen findings and that investigating the impact of hormone replacement therapy (HRT), as well as different oral hygiene practices and socio-economic backgrounds, on oral health would be valuable.
Regarding the potential contribution of probiotics in this population, Dr. Hale stated that they are already well documented as a means of balancing oral microbiomes, inhibiting periodontal pathogens and dampening local immune reactions and referenced clinical findings showing that Streptococcus salivarius strains BLIS K12 and BLIS M18 can help convert nitrate to nitrite.
“The additional assessment on the use of probiotics to support cardiovascular health to maintain or restore nitric oxide pathway in menopausal women is a compelling and logical next step for us to assess,” he said.
Source: International Dental Journal. doi: 10.1016/j.identj.2026.109518. “A Pilot Study Assessing the Oral Microbiome in Women of Menopausal Age: Do Oral Nitrate–Reducing Bacteria Play a Role?”. Authors: Katie Muddiman et al.
