Milk contains microRNAs (miRNA) that are shielded by small extracellular vesicles (sEVs). Beyond variations among individuals, many factors including nutrition play a role in shaping miRNA expression profiles. This study is to explore milk-derived sEVs-miRNA variations induced by inulin supplementation in sub-clinical mastitis-suffering cows. Fourteen lactating cows diagnosed with sub-clinical mastitis were equally assigned to either an inulin or a control group. Apart from total mixed rations, cows in the inulin group were provided with 300 g/d inulin during the morning feeding, while the control group did not receive any supplement. Following 1 week of adaptation and 5 weeks of treatment, sEVs-miRNA were isolated from the milk of each cow. RNA is subjected to high-throughput sequencing and differentially expressed (DE) miRNA (p < 0.05 and ∣log2FC∣> 1) were detected through bioinformatics analysis. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to examine the target genes of DE miRNA. A sum of 350 miRNA were discovered, including 332 in the control group and 249 in the inulin group. Among these, 9 miRNA showed differential expression within the two groups, including 3 upregulated and 6 downregulated in the inulin group. The DE miRNA participate in regulating organismal systems, cellular processes, and signal transduction, which may affect inflammatory response and milk production. Overall, our study provides insight into the micromolecular-level mechanism of inulin in alleviating sub-clinical mastitis in dairy cows

中文翻译：

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菊粉对亚临床乳腺炎奶牛牛奶中小细胞外囊泡 microRNAs 的影响


牛奶中含有被小细胞外囊泡 （sEV） 屏蔽的 microRNA （miRNA）。除了个体之间的差异外，包括营养在内的许多因素在塑造 miRNA 表达谱方面也起着作用。本研究旨在探讨亚临床乳腺炎奶牛中菊粉补充剂诱导的牛奶衍生的 sEVs-miRNA 变异。14 头诊断为亚临床乳腺炎的泌乳奶牛被平等分配到菊粉组或对照组。除了全混合日粮外，菊粉组奶牛在早晨饲喂时补充了 300 g/d 的菊粉，而对照组没有得到任何补充。经过 1 周的适应和 5 周的处理，从每头奶牛的牛奶中分离出 sEVs-miRNA。对 RNA 进行高通量测序，并通过生物信息学分析检测差异表达 （DE） miRNA （p < 0.05 和 ∣log2FC∣> 1）。进行基因本体论 （GO） 富集和京都基因与基因组百科全书 （KEGG） 通路分析，以检测 DE miRNA 的靶基因。共发现 350 个 miRNA，其中对照组 332 个，菊粉组 249 个。其中 9 个 miRNA 在两组内表达差异，其中菊粉组 3 个 miRNA 上调，6 个下调。DE miRNA 参与调节有机体系统、细胞过程和信号转导，这可能会影响炎症反应和产奶量。总体而言，我们的研究为菊粉缓解奶牛亚临床乳腺炎的微分子水平机制提供了见解