Randomized comparative double-blind study assessing the difference between topically applied microbiome supporting skincare versus conventional skincare on the facial microbiome in correlation to biophysical skin parameters.

BACKGROUND: There are trillions of live bacteria, of around 1000 different species, living in human skin which are considered essential for the balance and barrier function of the skin. The gut microbiome has been a subject of extensive research and evidence shows that the gut flora is affected by preservatives and processed foods. In conventional skincare, preservatives are used, and this raises the question of how it affects the skin flora and its balance. METHODS: A randomized double-blind study on 14 healthy volunteers ages 23-45 years old were advised to use microbiome-supporting (MS) products on one cheek and benchmark (BM) products on the other cheek daily for 3 weeks. To investigate how the skin was affected, the skin microbiome was analysed using 16 S rRNA sequencing and biophysical parameters were assessed using an Antera 3D camera. Measurements were performed before and after the 3 weeks of using the products. RESULTS: The use of MS products for 3 weeks significantly increased the total number of reads mapped to unique bacterial species (p < 0.05) and the number of different unique species (p < 0.05). In addition, the use of MS products significantly reduced redness (p < 0.05) and improved skin texture (p < 0.01). The use of BM products showed no significant difference in any of the parameters except improved skin texture (p < 0.05). Additionally, the MS side showed a significantly improved diversity (p < 0.05) compared with the BM side. The four major phyla found were, similarly to previous findings by others, Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes. Some of the most prevalent species were Cutibacterium acnes, Staphylococcus epidermidis and Pseudonomas aeruginosa. CONCLUSION: The findings of this study showed significant improvements in the microbiome and biophysical parameters within 3 weeks of using MS skincare alone, while BM skincare only gave significantly improved skin roughness. Importantly, the MS side gave a significantly improved bacterial Shannon diversity (p < 0.05) compared with the BM side. Regarding the biophysical parameters, the MS skincare gave significant improvements in several parameters compared with baseline. However, they were not yet significant when compared to using BM skincare and therefore a larger study population will be needed. Importantly, this is the first study to investigate how preservatives affect the facial microbiome in vivo and has raised a need for further investigation. These results together with further studies can lead to innovations within the cosmetic industry that promote healthier skin.

CONTEXTE: Il existe des milliers de milliards de bactéries vivantes, d'environ 1 000 espèces différentes, vivant dans la peau humaine, qui sont considérées comme essentielles pour l'équilibre et la fonction barrière de la peau. Le microbiome intestinal a fait l'objet de recherches approfondies, et des preuves montrent que la flore intestinale est affectée par les conservateurs et les aliments transformés. Dans les soins de la peau traditionnels, des conservateurs sont utilisés, ce qui soulève la question de leur effet sur la flore cutanée et son équilibre. MÉTHODES: Dans une étude randomisée en double aveugle, il a été conseillé à 14 volontaires en bonne santé âgés de 23 à 45 ans d'utiliser quotidiennement des produits nourrissant le microbiome (NM) sur une joue et des produits de référence sur l'autre joue pendant 3 semaines. Pour étudier l'effet sur la peau, le microbiome cutané a été analysé à l'aide d'un séquençage ARNr 16S, et les paramètres biophysiques ont été évalués à l'aide d'une caméra 3D Antera. Les mesures ont été réalisées avant et après les 3 semaines d'utilisation des produits. RÉSULTATS: L'utilisation de produits NM pendant 3 semaines a significativement augmenté le nombre total de résultats cartographiés pour des espèces bactériennes uniques (p < 0,05) et le nombre d'espèces uniques différentes (p < 0,05). En outre, l'utilisation de produits NM a significativement réduit la rougeur (p < 0,05) et amélioré la texture de la peau (p < 0,01). L'utilisation de produits de référence n'a montré aucune différence significative dans aucun des paramètres, à l'exception de l'amélioration de la texture de la peau (p < 0,05). En outre, les produits NM ont montré une diversité significativement améliorée (p < 0,05) par rapport aux produits de référence. Les quatre principaux embranchements identifiés étaient, de manière similaire aux résultats précédents d'autres études, les actinobactéries, les bacillota, les protéobactéries et les bactéroïdètes. Certaines des espèces les plus prévalentes étaient Cutibacterium acnes, Staphylococcus epidermidis et Pseudomonas aeruginosa. CONCLUSION: Les résultats de cette étude ont montré des améliorations significatives du microbiome et des paramètres biophysiques dans les 3 semaines suivant l'utilisation de soins de la peau NM seuls, tandis que les soins de la peau de référence n'ont permis qu'une amélioration significative de la rugosité de la peau. Il est important de noter que les produits NM ont permis une amélioration significative de la diversité bactérienne de Shannon (p < 0,05) par rapport aux produits de référence. En ce qui concerne les paramètres biophysiques, les soins de la peau NM ont apporté des améliorations significatives de plusieurs paramètres par rapport à l'entrée dans l'étude. Cependant, ils n'étaient pas encore significatifs par rapport à l'utilisation de soins de la peau de référence et, par conséquent, une étude avec une population plus importante sera nécessaire. Il est important de noter qu'il s'agit de la première étude examinant l'effet des conservateurs sur le microbiome facial in vivo et qu'elle a soulevé la nécessité d'une étude plus approfondie. Ces résultats, ainsi que des études complémentaires, peuvent conduire à des innovations au sein de l'industrie cosmétique qui favorisent une peau en meilleure santé.

Comparison of Moisturizing Creams for the Prevention of Atopic Dermatitis Relapse: A Randomized Double-blind Controlled Multicentre Clinical Trial.

Atopic dermatitis (AD) affects adults and children and has a negative impact on quality of life. The present multicentre randomized double-blind controlled trial showed a barrier-improving cream (5% urea) to be superior to a reference cream in preventing eczema relapse in patients with AD (hazard ratio 0.634, p = 0.011). The risk of eczema relapse was reduced by 37% (95% confidence interval (95% CI) 10-55%). Median time to relapse in the test cream group and in the reference cream group was 22 days and 15 days, respectively (p = 0.013). At 6 months 26% of the patients in the test cream group were still eczema free, compared with 10% in the reference cream group. Thus, the barrier-improving cream significantly prolonged the eczema-free time compared with the reference cream and decreased the risk of eczema relapse. The test cream was well tolerated in patients with AD.

Accumulation of sunscreen in human skin after daily applications: a study of sunscreens with different ultraviolet radiation filters.

BACKGROUND/PURPOSE: Sunscreen applied to the skin provides a considerable sun protection factor (SPF) even after 8 h. Sunscreen use for consecutive days may therefore result in an accumulation of the product. This study investigated the consequences of accumulation for SPF. METHODS: Two sunscreens, one containing organic and one containing particle ultraviolet radiation (UVR) filters (SPF 30) (2 mg/cm(2)), were used. Areas on the back of 22 volunteers were applied with sunscreen on 5 consecutive days, once daily (12 volunteers) and three times daily (10 volunteers), and phototested. The SPF was determined on Days 1, 3 and 5. RESULTS: One daily application of sunscreen did not result in an accumulation in the skin that significantly affected the SPF. However, three daily applications provided a significantly higher SPF for both the organic (mean SPF 1.56) and particle (mean SPF 2.45) sunscreen at Day 5 compared to Day 1 (P = 0.023 for both sunscreens). CONCLUSION: Sunscreens accumulate in the skin when applied in the recommended amounts three times daily. In conjunction with other sun protection strategies, sunscreen application on consecutive days prior to UVR exposure can result in a basic skin protection, which may help to prevent severe sunburns on sun holidays.

Novel method for studying photolability of topical formulations: a case study of titanium dioxide stabilization of ketoprofen.

Sunlight may decompose active substances and excipients in pharmaceuticals. This may cause formulation problems as well as induce adverse skin reactions. The photodecomposition of topical preparations may occur on the skin surface, but also deeper in the skin after penetration of light into the viable tissues. The aim of the present study was to investigate whether microparticles of titanium dioxide could protect against photodecomposition using ketoprofen as a photolabile model substance. The results showed quality differences between titanium dioxide, where surface-coated particles were superior to pharmaceutical grades in reducing the degradation in vitro. The protective effect was also studied in humans. The skin was treated for 3 h with the gels and then exposed to ultraviolet (UV) light (11.7 J/cm2 UVA and 5.4 mJ/cm2 UVB). Layers of the stratum corneum were then removed by consecutive tape strippings and assayed for content of ketoprofen. The remaining amount was higher in the different stratum corneum compartments after treatment with a gel containing 4% coated titanium dioxide compared with a transparent gel. Thus, surface-coated microparticles of titanium dioxide may well be of clinical benefit in protecting photolabile drug substances against sunlight.

Bioequivalence determination of topical ketoprofen using a dermatopharmacokinetic approach and excised skin penetration.

Ketoprofen is a photolabile drug. The aim of the present study was to compare the bioavailability of ketoprofen in a photo-stabilised formulation with a gel without photoprotection using a new dermatopharmacokinetic tape-stripping model and an established ex vivo penetration method using human skin. Analyses of the stratum corneum showed that during the first 45 min about 12 microg/cm2 ketoprofen was absorbed into the skin from the formulations. The area under the ketoprofen content-time curve (AUC0-6 h) for the ratio photo-stabilised gel/transparent gel was 73% with a 90% confidence interval (CI) 65-83. The rate of penetration of ketoprofen through isolated skin was approximately 0.2 microg/cm2 h for both formulations. AUC0-36 h for the ratio was 84% with 90% CI 64-105. Thus, the two methods did not disagree in terms of relative efficacy of the two gels. However, the difference obtained in vivo was statistically significant, whereas no significant data arise from the ex vivo study. Comparing the amount of ketoprofen in the skin after 45 min with the amount penetrated through the excised skin during 36 h, suggests a change in the thermodynamic activity of ketoprofen during the exposure. A supersaturated formulation may well have been formed initially due to evaporation of ethanol.