Unilever R&D, 64 Whitefield Main Road, Bangalore, Karnataka 560066, India.
J Med Microbiol. 2021 Sep;70(9). doi: 10.1099/jmm.0.001421.
The pH of skin is critical for skin health and resilience and plays a key role in controlling the skin microbiome. It has been well reported that under dysbiotic conditions such as atopic dermatitis (AD), eczema, etc. there are significant aberrations of skin pH, along with a higher level of compared to the commensal on skin. To understand the effect of pH on the relative growth of and , we carried out simple growth kinetic studies of the individual microbes under varying pH conditions. We demonstrated that the growth kinetics of is relatively insensitive to pH within the range of 5-7, while shows a stronger pH dependence in that range. Gompertz's model was used to fit the pH dependence of the growth kinetics of the two bacteria and showed that the equilibrium bacterial count of was the more sensitive parameter. The switch in growth rate happens at a pH of 6.5-7. Our studies are in line with the general hypothesis that keeping the skin pH within an acidic range is advantageous in terms of keeping the skin microbiome in balance and maintaining healthy skin.
皮肤的 pH 值对于皮肤健康和弹性至关重要，并且在控制皮肤微生物组方面起着关键作用。已有充分的报道表明，在皮肤微生物失衡的情况下，如特应性皮炎（AD）、湿疹等，皮肤 pH 值会出现显著的偏差，与皮肤上的共生菌相比，其水平更高。为了了解 pH 值对 和 的相对生长的影响，我们在不同 pH 值条件下对单个微生物进行了简单的生长动力学研究。我们证明了 在 5-7 的范围内，其生长动力学对 pH 值相对不敏感，而 在该范围内则表现出更强的 pH 值依赖性。我们使用 Gompertz 模型拟合了这两种细菌生长动力学的 pH 值依赖性，结果表明 的平衡细菌计数是更敏感的参数。这种生长速率的转变发生在 pH 值为 6.5-7 时。我们的研究与一般假设一致，即保持皮肤 pH 值处于酸性范围内有利于保持皮肤微生物组的平衡，维持皮肤健康。
