Distinct site-specific bacterial microbiota within and between skin physiologic types in healthy Koreans: a pilot study

Human skin is classified into sebaceous, moist, and dry, which influence the skin microbiome. However, variation within each type is poorly understood and may depend more on anatomical site than physiologic type. We analyzed bacterial communities from eight anatomical sites in ten healthy Korean adults using 16 S rRNA V1-V3 sequencing. Multivariate analysis showed that the anatomical site explained more variation in the microbiome than physiologic type. In dry skin, Cutibacterium was enriched in the dorsal forearm, whereas Kocuria was dominant on the sole. Within moist skin, Staphylococcus showed site-associated compositional differences, while the neck showed a trend toward higher Cutibacterium. Sebaceous scalp sites were rich in Lawsonella and had less Cutibacterium than facial sites. Despite limited species-level resolution of the V1-V3 region, heterogeneity was observed within the same physiologic type, indicating that anatomical site is an important determinant of microbiome structure. These results indicate distinct bacterial community structures both between and within physiologic skin types. These findings provide baseline insights into site-specific host-microbe interactions in healthy skin.