3. Discussion
SKIN
In this study, we investigated changes in skin biophysical parameters and microbiome in healthy subjects after 3 weeks of EPI-7 derived postbiotics application. Our results demonstrated that the topical application of the postbiotics substantially enhanced the skin barrier function as assessed by corneometer and TEWL, possibly due to the restoration of commensal microbial diversity. In addition, skin elasticity and dermal density were also significantly improved. Meanwhile, the metagenomics analysis revealed that the use of the postbiotics substantially altered the diversity of the skin microbiome, which included When describing metabolomics analysis, alpha diversity is a measure of the species diversity within a single ecosystem or a sample group. It provides information on the number of species and their relative abundance in a given area including the skin. Here, we considered two aspects when predicting alpha diversity in species. “Species richness” and “evenness” are the two components of alpha diversity that describe microbial diversity within a community. Species richness refers to the number of different species present in a community. It provides a simple count of the number of species within a sample group, thereby giving an idea of the overall number of different species present. Species evenness, on the other hand, refers to the distribution of individuals among species within a community. It measures how evenly the individuals are distributed among species within a sample group [In this study, the alpha diversity results based on “observed features” and “Chao1” indices considering the “richness” of microbial genus suggested that the topical application of EPI-7 clearly increased the normal microbial diversity after 3 weeks. Meanwhile, no statistically significant changes were found in the alpha diversity analysis considering the microbial “evenness” among each study group (Shannon, Simpson, and Pielou’s evenness). Therefore, we hypothesized that the EPI-7 postbiotics, including orotic acid treatment, did not significantly alter the dominance of a specific microorganism in the skin microbiome, but rather played a crucial role in enhancing the normally-distributed diversity of microbial species within the skin environment.Skin aging is the result of variations in the cutaneous structure and physiological changes [In a study involving 20 healthy women over 60, a topical cream containing a probiotics lysate of the bacterium Meanwhile, another previous study aimed to evaluate the moisturizing effect of a skin moisturizer containing paraprobiotics (heat-inactivated Bifidobacterium lactis and Lactobacillus plantarum) and its impact on the skin microbiome of healthy individuals. Fifty subjects were divided into a treatment group (25 individuals) and a control group (25 individuals), and the changes in transepidermal water loss (TEWL) and stratum corneum moisture (SCM) after 4 weeks of treatment were observed [In summary, this study highlighted the effect of EPI-7 derived postbiotics on biodiversity and microbial composition on the faces of healthy women. It can be speculated that microbial change reflects changes in skin physiology and appearance. Limitations include the size of the study population and short study period. Consequently, the present investigation provides early evidence indicating how postbiotic treatment may influence the phenotypes of skin aging and microbial diversity. Further thorough research, including an examination of postbiotic metabolites, is required to validate the results.