Supplementary Material for: Shifts in the Skin Microbiota after UVB Treatment in Adult Atopic Dermatitis

Background: The pathophysiology in atopic dermatitis (AD) is not fully understood, but immune dysfunction, skin barrier defects, and alterations of the skin microbiota are thought to play important roles. AD skin is frequently colonized with Staphylococcus aureus (S. aureus) and microbial diversity on lesional skin (LS) is reduced compared to on healthy skin. Treatment with narrow-band ultraviolet B (nb-UVB) leads to clinical improvement of the eczema and reduced abundance of S. aureus. However, in-depth knowledge of the temporal dynamics of the skin microbiota in AD in response to nb-UVB treatment is lacking and could provide important clues to decipher whether the microbial changes are primary drivers of the disease, or secondary to the inflammatory process. Objectives: To map the temporal shifts in the microbiota of the skin, nose, and throat in adult AD patients after nb-UVB treatment. Methods: Skin swabs were taken from lesional AD skin (n = 16) before and after 3 treatments of nb-UVB, and after 6–8 weeks of full-body treatment. We also obtained samples from non-lesional skin (NLS) and from the nose and throat. All samples were characterized by 16S rRNA gene sequencing. Results: We observed shifts towards higher diversity in the microbiota of lesional AD skin after 6–8 weeks of treatment, while the microbiota of NLS and of the nose/throat remained unchanged. After only 3 treatments with nb-UVB, there were no significant changes in the microbiota. Conclusion: Nb-UVB induces changes in the skin microbiota towards higher diversity, but the microbiota of the nose and throat are not altered.背景：特应性皮炎（atopic dermatitis, AD）的病理生理机制尚未完全明确，现有研究认为免疫功能异常、皮肤屏障缺陷及皮肤菌群改变在其发病过程中发挥重要作用。AD患者皮肤常定植有金黄色葡萄球菌（Staphylococcus aureus, S. aureus），且皮损皮肤（lesional skin, LS）的微生物多样性较健康皮肤有所降低。窄谱中波紫外线（narrow-band ultraviolet B, nb-UVB）治疗可实现湿疹的临床改善，并降低皮损处S. aureus的丰度。然而，目前尚缺乏AD患者皮肤菌群对nb-UVB治疗应答的时间动态变化的深入研究，此类研究或可为阐明微生物变化是疾病的原发驱动因素，还是炎症过程的继发改变提供关键线索。 目的：明确成人AD患者接受nb-UVB治疗后，皮肤、鼻腔及咽部菌群的时间偏移特征。 方法：研究人员从16例AD患者的皮损皮肤处采集拭子样本，分别在3次nb-UVB治疗前后，以及完成6~8周全身治疗后进行采样；同时采集非皮损皮肤（non-lesional skin, NLS）、鼻腔及咽部的样本。所有样本均通过16S rRNA基因测序进行菌群特征分析。 结果：经6~8周治疗后，AD患者皮损皮肤的菌群多样性显著升高，而非皮损皮肤、鼻腔及咽部的菌群未发生明显变化；仅接受3次nb-UVB治疗后，菌群未出现显著改变。 结论：nb-UVB治疗可诱导皮肤菌群向更高多样性方向转变，但鼻腔与咽部的菌群未出现明显改变。