Personal Care and Aroma, DSM Nutritional Products Ltd, Kaiseraugst, Switzerland.
Biodata and Translation, DSM Nutritional Products, Lexington, Massachusetts, USA.
Int J Cosmet Sci. 2024 Feb;46(1):71-84. doi: 10.1111/ics.12910. Epub 2023 Oct 6.
Ultraviolet radiation (UVR) is a known environmental key factor for premature skin ageing. Only few scientific evidence is available to support the effects of UVR on the skin microbiome. This in vivo pilot study aimed to evaluate the impact on the skin microbiome upon erythemal UV exposure and the protection of UV-exposed skin microbiome by UV filters.
Ten female volunteers were treated with an sun protection factor (SPF) 20 sunscreen and placebo formulation (without UV filters) on their upper middle backs and irradiated with an erythemal dose (2 MED) by a solar simulator. Skin swabbing samples from four zones (i.e., unexposed, exposed, sunscreen- and placebo-treated on exposed skin) were collected for the microbiome analysis before and 2 h after UV exposure, respectively, and processed via shallow 16S rRNA Amplicon and Shotgun metagenomic sequencing. An in vitro UV method was developed to confirm the protection of isolated bacterial strains by single UV filters and combinations.
Alpha diversity was impacted by significant inter-individual differences and by treatment rather than by irradiation. Cutibacterium acnes was found to be the most abundant and a confounding factor for diversity. On a species level, Lactobacillus crispatus was negatively associated with UVR and placebo treatment, whereas there was a positive association with sunscreen treatment. The sunscreen treatment also favoured an interaction network with central Micrococcus genus. The in vitro results showed that both single UV filters and combinations had specific effects on the survival rates of L. crispatus, C. acnes, and Staphylococcus epidermidis.
We identified potential microorganisms and bacterial interactions that were associated with an SPF 20 sunscreen treatment. The specific protection of L. crispatus as a key player in the UV-exposed skin microbiome and reduction of C. acnes population by UV filters might lead to new cosmetic concepts for photoprotection.
紫外线（UVR）是导致皮肤过早衰老的已知环境关键因素。仅有少量科学证据支持 UVR 对皮肤微生物组的影响。本体内试验研究旨在评估红斑性 UV 暴露对皮肤微生物组的影响，以及 UV 滤光剂对 UV 暴露皮肤微生物组的保护作用。
10 名女性志愿者在上背部中部使用 SPF20 防晒霜和不含 UV 滤光剂的安慰剂制剂进行处理，并通过太阳模拟器接受红斑剂量（2MED）照射。在 UV 暴露前和暴露后 2 小时，分别从四个区域（即未暴露、暴露、暴露皮肤的防晒霜和安慰剂处理区）采集皮肤拭子样本进行微生物组分析，然后通过浅层 16S rRNA 扩增子和 Shotgun 宏基因组测序进行处理。开发了一种体外 UV 方法，以确认单种 UV 滤光剂和组合对分离细菌株的保护作用。
多样性受到显著个体间差异和处理而不是照射的影响。痤疮丙酸杆菌是最丰富的细菌，也是多样性的混杂因素。在物种水平上，卷曲乳杆菌与 UVR 和安慰剂处理呈负相关，而与防晒霜处理呈正相关。防晒霜处理还促进了以微球菌属为中心的相互作用网络。体外结果表明，单种 UV 滤光剂和组合对卷曲乳杆菌、痤疮丙酸杆菌和表皮葡萄球菌的存活率都有特定的影响。
我们确定了与 SPF20 防晒霜处理相关的潜在微生物和细菌相互作用。作为 UV 暴露皮肤微生物组中关键成员的卷曲乳杆菌的特异性保护作用，以及 UV 滤光剂对痤疮丙酸杆菌种群的减少，可能为光保护带来新的化妆品概念。
