Enlarged facial pores are associated with skin barrier impairment and microbiome dysbiosis in young Chinese women

OBJECTIVE: Enlarged facial pores represent a prominent and widely concerning skin condition, as well as a challenging issue in skin care. The unique structure of pores provides a favourable habitat for microorganisms. Consequently, it is of great significance to explore the relationship between pore size, skin microbiota and their microenvironment. This study is the first to investigate the correlations between pore area, skin physiological and microbiota characteristics, providing a theoretical basis for the care of skin with enlarged pores. METHODS: Based on VISIA CR photographs, 199 women aged 18-35 years living in Shanghai were enrolled and categorized into four groups (P1, P2, P3 and P4) according to pore area, ranging from the smallest (P1) to the largest (P4). Non-invasive biophysical techniques and 16S rRNA high-throughput sequencing were employed to analyse facial skin physiological parameters and skin microbiome, respectively. RESULTS: As facial pore size increased, trans-epidermal water loss (TEWL), haemoglobin and melanin levels increased significantly, whereas skin elasticity decreased. Sebum exhibited an increasing trend, with the P4 group showing significantly higher sebum than the P2 group. Alpha diversity, as assessed by the Shannon index, decreased significantly as pore size increased, suggesting that enlarged pores may be closely associated with skin microbiome dysbiosis. Furthermore, with increasing pore size, the abundance of Cutibacterium increased significantly, whereas those of Pseudomonas, Streptococcus and Rhodococcus decreased. Correlation analysis of skin physiological parameters revealed that sebum was positively associated with TEWL, haemoglobin, and a value. Meanwhile, the abundance of Cutibacterium was significantly positively correlated with sebum, haemoglobin and a value. Correlation network analysis of skin microbial communities indicated significantly different correlation patterns for P1 and P4. Collectively, these findings suggest that sebum and Cutibacterium abundance play critical roles in regulating pore size. CONCLUSION: Enlarged pores were associated with excessive sebum production, reduced skin elasticity and increased TEWL, indicative of compromised skin barrier function. Furthermore, pore size significantly modulated the structure of the local skin microbiome, as regions with different pore sizes exhibited marked disparities in microbial diversity and abundance. These findings highlight the potential role of skin microbiome dysbiosis in the pathogenesis of pore enlargement.