Abstract
Over time biological skin properties change with age, which is caused by both external and internal factors such as UV and hormone balance. In particular, skin parameters of growing children differ depending on when they are measured. Many reports have been presented of the skin characteristics of adults and children from measurements on the inner arm or face. But there have been very few studies on scalps. Recently the importance of microbiome on the skin has been discussed and it seems to be highly related with skin parameters. In this report, we examined the biophysical measurements and analyzed the microbiome on the scalps of a group of three-year-old girls and their mothers. We discovered many differences in their microbiome between the children and the mothers who lived in same environment. In skin parameters, the amounts of sebum and pH of children's scalp were significantly lower than those of mothers, while the volume of sweat was remarkably higher and skin conductance also tended to be higher than for mothers. From our microbiome analysis, children have many varieties of genera existing on the scalp compared with mothers. Principal component analysis (PCA) from our microbiome data suggested that different bacteria contribute to the microbiome on the scalps of children and mothers: Streptococcus for children and Cutibacterium for mothers.
