Objective: To evaluate the impact of oral intake of Hyaluronic Acid (HA) on skin health. Background: HA, an endogenous substance in the human body, plays a key role in skin health. However, its concentration in the skin decreases significantly with age. Previous studies suggested that oral intake of HA can supplement the body's HA level, but did not reveal the effects on different age groups and skin types. Methods: A double‐blind, randomized clinical trial with 129 female participants, covering young and elderly groups and differnet skin types, was conducted to assess the efficacy of orally administered HA on skin health. Results: Oral administration of HA significantly promoted skin hydration after 2‐8 weeks among both young and elderly groups. Skin tone improvement was observed after 4‐8 weeks, while an increase in epidermal thickness was noted after 12 weeks. Conclusion: This study provides direct evidence supporting the clinical efficacy of oral intake of HA in promoting skin health.

The skin microbiota barrier participates in skin barrier function in addition to the physical, chemical, and immunological protective barriers, and is affected by environmental aggressors and skincare regimens. To better understand the exact effects of real-life environmental conditions on the skin and determine the protective methods, this study investigates the effects of three topical cosmetic moisturizers (water gel moisturizers with/without yeast extract (Moisturizers K and C) and a thick-emulsion cream moisturizer (Moisturizer L)) on clinical and skin microbiome endpoints in the presence of environmental aggressors during an 8-week, randomized controlled, triple-blind clinical trial with 110 participants, and molecular- as well as biomarker-level endpoints on ex vivo skin explants after exposure to simulate urban environmental conditions. The results show that all moisturizers are well-tolerated and improve skin barrier function and surface moisture content from the baseline, and the improvement is maintained at the last analysis point (3 days after trial completion). Compared with the untreated control areas (samples taken from the upper chest), treatment with Moisturizer K prevented a reduction in bacterial and fungal richness, and increased the change ratio of the relative abundance of commensal bacteria, such as Staphylococcus epidermidis and Ralstonia, at the treated sites (samples taken from the forehead). Moreover, Moisturizer K-treated ex vivo skin explants had higher levels of caspase 14 (a marker of skin barrier function), collagen I, and elastin (structure components), and lower levels of aryl hydrocarbon receptor (AHR; activated by air pollutants) and interleukin-6 (IL-6) than those in explants treated with other moisturizers and in the untreated areas of the skin. These results suggest that a skin postbiotic moisturizer with yeast extract supports the regulation of the skin’s microbiome balance and may provide a holistic barrier (involving skin microbiome, physical, chemical, and immune barriers) to protect the skin against environmental aggressors.

In the rosacea an unstable skin microbiota is significant for disease progression. However, data on the influence on the skin microbiota of treatment with systemic antibiotics are limited. This single-arm trial recruited patients with rosacea. Oral minocycline 50 mg was administered twice daily for 6 weeks. The lesions on the cheek and nose were sampled for 16S rRNA amplicon sequencing and metagenomic sequencing at baseline, 3 weeks and 6 weeks of treatment. Physiological parameters were detected using non-invasive instruments. After treatment, distribution of the Investigator Global Assessment scores changed significantly. For the skin microbiota, a notable increase in α-diversity and a shift of structure were observed after treatment. Treatment was accompanied by a reduction in the relative abundance of Cutibacterium and Staphylococcus, indicating negative correlations with increased bacterial metabolic pathways, such as butyrate synthesis and L-tryptophan degradation. The increased butyrate and tryptophan metabolites would be conducive to inhibiting skin inflammation and promoting skin barrier repair. In addition, the abundance of skin bacterial genes related to tetracycline resistance and multidrug resistance increased notably after antibiotic treatment.

Objective: This study was to verify if the skin cleanser could help decrease the infection ratio of Demodex Folliculorum in acne patients. Methods: 132 participants with mild to moderate vulgaris acne participated in this monocentric, prospective, double-blind study. Dermatologists grading and Standardized Skin Surface Biopsy were performed in baseline and after using cleanser only 7 d later. Results: There was no significant difference between the 2 times for each type of acne, but the number of Demodex Folliculorum was significantly decreased compared with baseline. There was no relationship between the number of Demodex Folliculorum and the total number of acne lesions. Limitations: Short follow-up time in 7 d. Conclusion: Using the cleanser could decrease the average number of Demodex Folliculorum in only 7 d in mild to moderate acne patients. There is no relationship between Demodex and acne lesions number.