Seborrheic dermatitis (SD) is a common disease of the human scalp that causes physical damage and psychological problems for patients. Studies have indicated that dysbiosis of the scalp microbiome results in SD. However, the specific fungal and bacterial microbiome changes related to SD remain elusive. To further investigate the fungal and bacterial microbiome changes associated with SD, we recruited 57 SD patients and 53 healthy individuals and explored their scalp microbiomes using next generation sequencing and the QIIME and LEfSe bioinformatics tools. Skin pH, sebum secretion, hydration, and trans-epidermal water loss (TWEL) were also measured at the scalp. We found no statistically significant differences between the normal and lesion sites in SD patients with different subtypes of dandruff and erythema. However, the fungal and bacterial microbiome could differentiate SD patients from healthy controls. The presence of Malassezia and Aspergillus was both found to be potential fungal biomarkers for SD, while Staphylococcus and Pseudomonas were found to be potential bacterial biomarkers. The fungal and bacterial microbiome were divided into three clusters through co-abundance analysis and their correlations with host factors indicated the interactions and potential cooperation and resistance between microbe communities and host. Our research showed the skin microbe dysbiosis of SD and highlighted specific microorganisms that may serve as potential biomarkers of SD. The etiology of SD is multi-pathogenetic-dependent on the linkage of several microbes with host. Scalp microbiome homeostasis could be a promising new target in the risk assessment, prevention, and treatment of SD disease.

脂溢性皮炎（SD）是人类头皮的一种常见疾病，会给患者带来身体伤害和心理问题。研究表明，头皮微生物群的失调会导致 SD。然而，与 SD 相关的特定真菌和细菌微生物组变化仍然难以捉摸。为了进一步研究与 SD 相关的真菌和细菌微生物组变化，我们招募了 57 名 SD 患者和 53 名健康人，并使用下一代测序以及 QIIME 和 LEfSe 生物信息学工具探索了他们的头皮微生物组。还在头皮处测量了皮肤 pH 值、皮脂分泌、水合作用和跨表皮水分流失 (TWEL)。我们发现具有不同头皮屑和红斑亚型的 SD 患者的正常和病变部位之间没有统计学上的显着差异。然而，真菌和细菌微生物组可以区分 SD 患者与健康对照。的存在马拉色菌和曲霉均被发现是 SD 的潜在真菌生物标志物，而葡萄球菌和假单胞菌被发现是潜在的细菌生物标志物。通过共丰度分析将真菌和细菌微生物群分为三个簇，它们与宿主因素的相关性表明微生物群落与宿主之间的相互作用和潜在的合作和抵抗。我们的研究显示了 SD 的皮肤微生物生态失调，并突出了可能作为 SD 潜在生物标志物的特定微生物。SD 的病因是多病原体的，依赖于几种微生物与宿主的联系。头皮微生物组稳态可能是 SD 疾病风险评估、预防和治疗的一个有希望的新目标。