Is There a Relationship between Transepidermal Water Loss and Microbial Biodiversity on the Skin?

As described in previous work, TEWL (transepidermal water loss) is used as an indicator of skin barrier function and health by scientists at top research institutions. However, it is known to be unreliable because many other factors determine its value, such as humidity, temperature and moisture content of the skin. In this study, to help elucidate whether it is a good indicator of the health of skin, we used bivariate linear correlation analysis and the Pearson correlation coefficient to compare values of skin microbial biodiversity with TEWL. In 2017 in our previous work, microbial biodiversity was found to currently be the only reliable indicator of skin health. Diversity was also compared with moisture content and pH, along with TEWL vs. moisture. All data was taken from the use of human participants in our previous work in 2018. Results showed no linear correlation between microbial biodiversity and TEWL rates or any of the other variables. This suggests the need for researchers to make conclusions about TEWL rates and their meaning with regards to skin function and health, with caution. Future work should consider the possibility of non-linear relationships, use larger datasets and mitigate against the effect of non-normally distributed data.