Short-Term Topical Retinol Use Is Associated With Improved Pore-Related Parameters and Shifts in the Facial Skin Microbiome

초록

Background Retinol is widely used for acne-prone skin and is known to affect keratinization and sebum-related processes. However, longitudinal human data on how topical retinol use relates to changes in the facial skin microbiome remain limited. Aims To evaluate temporal changes in facial pore-related parameters and the skin microbiome during short-term use of a retinol-containing product in individuals with acne-prone skin, and to explore whether the addition of a low-dose polylysine altered the overall response pattern. Methods Forty-three Korean women with acne-prone skin used a retinol-containing product for 4 weeks. Skin parameters and facial skin microbiome profiles, assessed by 16S rRNA gene sequencing, were evaluated at baseline (week 0), week 1, and week 4. Participants used either 0.03% retinol alone or 0.03% retinol plus 0.0002% polylysine. As no broad between-formulation differences in community structure were detected, the primary longitudinal microbiome analyses were performed in the pooled cohort. Results Acne lesion counts, including whiteheads, blackheads, and inflammatory papules, decreased at week 4 compared with baseline. Selected skin physiological parameters also improved, with reductions in transepidermal water loss and sebum level at week 4. Pore-related parameters, including total pore volume, maximum pore depth, pore count, and pore area, were also reduced at week 4 compared with baseline. Microbiome analyses demonstrated significant temporal shifts in community composition across visits, along with significant changes in alpha diversity over time. Conclusions In this exploratory study, short-term topical retinol use was associated with improvements in multiple acne- and pore-related skin parameters, together with concurrent temporal shifts in the facial skin microbiome. Larger studies with longer follow-up and mechanistic endpoints are needed to clarify the clinical relevance and underlying biological pathways.

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