Salivary estrone and estradiol are associated with oral microbiome profiles in aging women

OBJECTIVES: To explore whether salivary estrogens (estrone and estradiol) are associated with oral microbiome composition in aging women, and to assess the oral cavity as a potential sentinel of systemic hormonal changes during midlife. MATERIALS AND METHODS: Cross-sectional study including 30 women aged 40-65 years. Saliva and microbial specimens were collected from four oral ecological niches (buccal mucosa, tongue dorsum, supragingival plaque, subgingival plaque). Microbiome composition and diversity were assessed by 16S rRNA gene sequencing, ecological indices, and co-occurrence network analysis. Salivary estrone and estradiol were quantified, and associations with oral health and microbial profiles were evaluated. RESULTS: Estrone levels declined significantly with age and were associated with hyposalivation and lower oral health scores. Estrone was linked to increased microbial diversity on the tongue dorsum and enrichment of taxa such as Porphyromonas. In contrast, estradiol was positively associated with commensal genera (Streptococcus, Lactobacillus) and negatively with periodontal-associated taxa (Fusobacterium, Prevotella). Co-occurrence networks revealed niche-specific microbial shifts associated with estrogen levels. CONCLUSIONS: Salivary estrogens, particularly estrone, shape oral microbial communities in aging women. The oral cavity may act as a window into systemic hormonal changes, supporting its role as a non-invasive sentinel of women's health during midlife.