Integrated Multi-Omics Analysis Reveals that Rumen Fluid Transplantation Reprograms Duodenal Function and Promotes Subcutaneous Fat Deposition in Xizang Sheep

To systematically evaluate the effects of rumen fluid transplantation (RFT) on small intestinal function and fat deposition in ruminants, this study used Tibetan sheep as a model and employed a comprehensive approach including histological analysis, transcriptome sequencing, targeted and non-targeted metabolomics, and 16S rRNA microbial sequencing to perform multi-level analysis of duodenal structure, metabolic regulation, microbiota composition, and subcutaneous fat phenotype. Results showed that RFT significantly promoted subcutaneous fat cell hypertrophy and lipid droplet deposition, and simultaneously improved duodenal tissue structure, manifested as increased villus height and width, deepened crypts, and increased goblet cell number. Transcriptome analysis revealed significant upregulation of genes related to energy metabolism and tissue remodeling, including PMCH, HAMP, and MMP9. Metabolome results showed that differentially metabolites were mainly enriched in glycerophospholipid metabolism and the ABC transport pathway, with increased levels of fatty acids (myristic acid, palmitoleic acid, and arachidonic acid) and a directed adjustment in bile acid composition (decreased GUCA and TLCA, and increased UDCA/TUDCA). Microbial analysis revealed that the Ruminococcus_gauvreauii_group is associated with steroid and inflammatory lipid metabolism, while the Lachnospiraceae_NK3A20_group is primarily associated with fatty acid and glycerophospholipid metabolism. In summary, rumen fluid transplantation enhances duodenal absorptive function through multi-level synergistic regulation, thereby promoting host fat deposition.

为系统评估瘤胃液移植（rumen fluid transplantation, RFT）对反刍动物小肠功能与脂肪沉积的影响，本研究以藏羊为模型，采用组织学分析、转录组测序、靶向与非靶向代谢组学以及16S rRNA微生物测序等综合手段，对十二指肠结构、代谢调控、菌群组成以及皮下脂肪表型开展多维度分析。研究结果显示，瘤胃液移植可显著促进皮下脂肪细胞肥大与脂滴沉积，同时改善十二指肠组织结构，具体表现为绒毛高度与宽度增加、隐窝加深以及杯状细胞数量增多。转录组分析表明，能量代谢与组织重塑相关基因（包括PMCH、HAMP及MMP9）的表达显著上调。代谢组学结果显示，差异代谢物主要富集于甘油磷脂代谢与ABC转运通路，脂肪酸（肉豆蔻酸、棕榈油酸与花生四烯酸）水平升高，且胆汁酸组成呈现定向调控趋势：GUCA与TLCA水平降低，UDCA/TUDCA水平升高。微生物组分析揭示，Ruminococcus_gauvreauii_group与类固醇及炎症性脂质代谢相关，而Lachnospiraceae_NK3A20_group则主要参与脂肪酸与甘油磷脂代谢。综上，瘤胃液移植可通过多维度协同调控增强十二指肠吸收功能，进而促进宿主脂肪沉积。