The pathogenesis of atopic dermatitis (AD) involves complex factors, including gut microbiota and immune modulation, which remain poorly understood. The aim of this study was to restore gut microbiota via fecal microbiota transplantation (FMT) to ameliorate AD in mice. FMT was performed using stool from donor mice. The gut microbiota was characterized via 16S rRNA sequencing and analyzed using Quantitative Insights into Microbial Ecology 2 with the DADA2 plugin. Gut metabolite levels were determined by measuring fecal short-chain fatty acid (SCFA) contents. AD-induced allergic responses were evaluated by analyzing blood parameters (IgE levels and eosinophil percentage, eosinophil count, basophil percentage, and monocyte percentage), the levels of Th1 and Th2 cytokines, dermatitis score, and the number of mast cells in the ileum and skin tissues. Calprotectin level was measured to assess gut inflammation after FMT. FMT resulted in the restoration of gut microbiota to the donor state and increases in the levels of SCFAs as gut metabolites. In addition, FMT restored the Th1/Th2 balance, modulated Tregs through gut microbiota, and reduced IgE levels and the numbers of mast cells, eosinophils, and basophils. FMT is associated with restoration of gut microbiota and immunologic balance (Th1/Th2) along with suppression of AD-induced allergic responses and is thus a potential new therapy for AD.

特应性皮炎 (AD) 的发病机制涉及复杂的因素，包括肠道微生物群和免疫调节，这些因素仍然知之甚少。本研究的目的是通过粪便微生物群移植 (FMT) 恢复肠道微生物群，以改善小鼠的 AD。使用来自供体小鼠的粪便进行 FMT。通过 16S rRNA 测序对肠道微生物群进行表征，并使用带有 DADA2 插件的 Quantitative Insights into Microbial Ecology 2 进行分析。通过测量粪便短链脂肪酸 (SCFA) 含量来确定肠道代谢物水平。通过分析血液参数（IgE 水平和嗜酸性粒细胞百分比、嗜酸性粒细胞计数、嗜碱性粒细胞百分比和单核细胞百分比）、Th1 和 Th2 细胞因子水平、皮炎评分和回肠肥大细胞数量和皮肤组织。测量钙卫蛋白水平以评估 FMT 后的肠道炎症。FMT 导致肠道微生物群恢复到供体状态，并增加作为肠道代谢物的 SCFA 水平。此外，FMT 恢复了 Th1/Th2 平衡，通过肠道微生物群调节 Tregs，并降低 IgE 水平和肥大细胞、嗜酸性粒细胞和嗜碱性粒细胞的数量。FMT 与恢复肠道微生物群和免疫平衡 (Th1/Th2) 以及抑制 AD 诱导的过敏反应有关，因此是一种潜在的 AD 新疗法。并降低 IgE 水平和肥大细胞、嗜酸性粒细胞和嗜碱性粒细胞的数量。FMT 与恢复肠道微生物群和免疫平衡 (Th1/Th2) 以及抑制 AD 诱导的过敏反应有关，因此是一种潜在的 AD 新疗法。并降低 IgE 水平和肥大细胞、嗜酸性粒细胞和嗜碱性粒细胞的数量。FMT 与恢复肠道微生物群和免疫平衡 (Th1/Th2) 以及抑制 AD 诱导的过敏反应有关，因此是一种潜在的 AD 新疗法。