Salivary pH Modulation and Antimicrobial Properties of Oregano-Oil Jelly in Relation to Menstrual and Menopausal Status.

Salivary pH plays a critical role in oral health by influencing enamel demineralization, buffering capacity, and the ecology of oral microbiota. Essential oils such as (oregano) possess well-documented antimicrobial properties that may reduce acidogenic bacterial activity. However, the effects of edible delivery systems like jellies on salivary pH modulation and their potential interactions with hormonal states remain poorly understood. This study evaluated the in vitro antimicrobial activity of an oregano-oil-based jelly formulation against standard bacterial (, , and ) and fungal () strains using the Kirby-Bauer disc diffusion method. Additionally, a human trial ( = 91) measured salivary pH before and after administration of the oregano-oil jelly. Participants were characterized by age, smoking status, menopausal status, and presence of menstruation. Multiple linear regression was used to identify predictors of final salivary pH. The oregano-oil jelly demonstrated strong in vitro antimicrobial activity, with inhibition zones up to 8 mm for and . In vivo, mean unstimulated salivary pH increased from 6.94 to 7.07 overall, indicating a mild alkalinizing effect. However, menstruating participants showed a significant decrease in final pH (from 7.03 to 6.78). Multiple regression identified menstruation as a significant negative predictor (β = -0.377, < 0.001) and initial pH as a positive predictor (β = +0.275, = 0.002). Menopausal status was not a significant predictor, likely due to the small sample size. Oregano-oil jellies may represent a promising natural approach to support oral health by increasing salivary pH and providing strong antimicrobial activity. However, physiological states such as menstruation can significantly modulate this response, underscoring the importance of personalized or phase-aware oral care strategies. Further studies with larger, diverse cohorts and controlled hormonal assessments are needed to validate these findings and optimize product formulations.