Abstract:

The in vitro and in vivo evaluation methods of microecological skin care products were summarized. Cosmetics can regulate skin microecological balance by directly changing the number, growth metabolism, community structure, and population effect of skin microorganisms, or by regulating skin immune response and improving skin physiological function. The number, growth and metabolism level, population effect of skin microorganisms and skin immune response status are often evaluated by in vitro method. Skin microbial diversity, community structure, and skin physiological state are often tested by human methods, combined with high-throughput sequencing technologies such as 16S rRNA amplicon sequencing, ITS amplicon sequencing, and shotgun metagenomic sequencing. Different evaluation methods have different dimensions and advantages. The in vitro method is more targeted and the test conditions are easy to control, but the model is too simple and lack of activity. In contrast, clinical trials are more holistic and in line with real use scenarios, but it is difficult to qualitative analyze the complex causal relationship among individuals, product use and microbiome changes. In the process of efficacy evaluation, the combination of in vitro and in vivo can complement the limitations of different evaluation methods to a certain extent, and can provide a more complete evidence chain for the efficacy evaluation of products.

Key words: skin microbiome, efficacy assessment, in vitro, animal model, amplicon sequencing, metagenome