Effects of Inhaling the Cypress Essential Oil Complex on the Nasal Microbiome

Background: Aromatherapy using natural essential oils has been proposed as a complementary strategy to prevent respiratory infections, particularly in elderly populations vulnerable to microbial colonization and antibiotic resistance. Objective: To evaluate the effect of inhaling the cypress essential oil complex on the nasal microbiome. Methods: A clinical study was conducted with 14 participants (mean age: 73 years) who were randomly assigned to either a treatment group (n = 8) or placebo group (n = 6). The treatment group was exposed to a natural essential oil complex containing cypress, lavender, eucalyptus, pine needle, rosemary, German chamomile, and bergamot oils for 3 hours daily over 4 weeks. The placebo group received a 1/100 dilution of the formulation. Nasal swabs were collected before and after treatment and were analyzed for changes in microbial composition. Statistical significance was assessed using the paired t-test. Results: The treatment group exhibited a significant reduction in the genus Staphylococcus (1.92% to 0.62%, p < 0.05) and a decrease in Streptococcus pneumoniae (1.04% to 0.87%). In contrast, the placebo group experienced minimal or no adverse changes. No adverse effects were reported during the study period. Conclusion: Inhalation of the cypress essential oil complex was associated with a reduction in nasal colonization by potential respiratory pathogens in older adults. These preliminary findings suggest a possible microbiome- modulating effect that warrants further investigation in larger, outcome-based clinical studies.