Research Laboratories, Nippon Menard Cosmetic Co., Ltd., Nagoya, Japan.
Fasmac Co., Ltd., Atsugi, Japan.
Int J Cosmet Sci. 2023 Jun;45(3):362-372. doi: 10.1111/ics.12842. Epub 2023 Apr 3.
The present study investigated the relationship between the skin bacterial and fungal microbiomes and skin pH at sebaceous sites, namely, the forehead, cheek and upper chest. We also examined the relationship between the skin microbiome and transepidermal water loss (TEWL), which is an indicator of rough skin.
Thirty healthy Japanese subjects (15 females and 15 males) were enrolled as subjects. The forehead, cheek and upper chest were examined in August (summer) and February (winter). Skin surface samples were collected using the swab method, and the 16s rRNA and ITS regions were analysed using next-generation sequencing. Skin pH and TEWL were also assessed.
The changes observed in the skin microbiome were associated with season-dependent changes in skin pH. An increase in skin pH at the forehead and cheek was associated with a higher relative abundance of Cutibacterium spp., a reduction in bacterial diversity, and a lower relative abundance of Staphylococcus spp. A decrease in skin pH at the upper chest was associated with a higher relative abundance of Malassezia restricta, a lower relative abundance of M. sympodialis and decrease in fungal diversity. Moreover, these changes were also associated with an increase in TEWL.
The present results indicate that changes in skin pH are associated with changes in the skin bacterial and fungal microbiomes at sebaceous sites. The changes observed in the skin microbiome were also associated with rough skin.
本研究调查了皮脂部位（即额头、脸颊和上胸部）的皮肤细菌和真菌微生物组与皮肤 pH 值之间的关系。我们还研究了皮肤微生物组与经皮水分流失（TEWL）之间的关系，TEWL 是粗糙皮肤的一个指标。
30 名健康的日本受试者（15 名女性和 15 名男性）被纳入研究对象。在 8 月（夏季）和 2 月（冬季）检查额头、脸颊和上胸部。使用拭子法采集皮肤表面样本，并使用下一代测序分析 16s rRNA 和 ITS 区。还评估了皮肤 pH 值和 TEWL。
皮肤微生物组的变化与皮肤 pH 值的季节性变化有关。额头和脸颊的皮肤 pH 值升高与 Cutibacterium spp. 的相对丰度增加、细菌多样性减少以及 Staphylococcus spp. 的相对丰度降低有关。上胸部皮肤 pH 值降低与 Malassezia restricta 的相对丰度增加、M. sympodialis 的相对丰度降低以及真菌多样性减少有关。此外，这些变化也与 TEWL 的增加有关。
本研究结果表明，皮肤 pH 值的变化与皮脂部位的皮肤细菌和真菌微生物组的变化有关。皮肤微生物组的变化也与粗糙皮肤有关。
