Abstract:

Understanding the changes in the skin physiological parameters, skin microbiome and their associated relationship during aging remains largely unknown. To better understand this phenomenon, we investigated 310 healthy females aged 18-60 years randomly selected from a community in Shanghai from July to August 2021. Multiple skin physiological parameters were measured by non-invasive instrumental methods, and the facial skin microbiome was analyzed by 16S rRNA sequencing. The results show that with the increase of age, skin sebum content and transepidermal water loss （TEWL） decrease, while the skin hydration is affected by age and in different age groups it presents different changing rules. Additionally, the skin color （ITA°） becomes darker, and the skin elasticity decreases, especially significantly appearing after the age of 25 years old （P<0.001）. The Shannon index is found to increase, indicating that the skin bacteria diversity increases with age. The analysis of species composition indicates that the abundance of Actinobacteria shows a decreasing trend, while Proteobacteria shows an increasing trend with age. Accordingly, at the genus level, the abundance of Cutibacterium decreases significantly, while the abundance of Streptococcus and Pseudomonas shows an increasing trend with age. Furthermore, spearman correlation analysis reveals strong correlations between the skin physiological parameters and the microbiota. Notably, age is an important factor affecting the changes of skin physiological parameters and skin bacteria. In conclusion, these results show that the skin physiological parameters and microbiota characteristics of females undergoes age-associated alterations. To some extent, these characteristics can be regarded as age markers, and these results can guide the development of cosmetics.

Key words: age, aging, female skin, physiological parameters, skin microbiota