Integrated multi-omics analysis reveals that rumen fluid transplantation reprograms duodenal function and promotes subcutaneous fat deposition in Xizang sheep

Rumen fluid transplantation (RFT) has emerged as a promising strategy for modulating rumen microecology and host metabolism in ruminants. However, its systematic effects on small intestinal function and peripheral fat deposition remain inadequately understood, particularly in high-altitude adapted breeds such as Xizang sheep. RFT significantly promoted subcutaneous adipocyte hypertrophy and lipid droplet accumulation, alongside duodenal structural remodeling with increased villi, crypt depth, and goblet cells. Transcriptomics revealed upregulation of PMCH , HAMP , and MMP9 related to energy metabolism. Metabolomics showed enrichment in glycerophospholipid metabolism and ABC transporters, with elevated fatty acids (myristic, palmitoleic, arachidonic acid) and altered bile acids (decreased GUCA/TLCA, increased UDCA/TUDCA). Microbial analysis linked Ruminococcus_gauvreauii_group to steroid and inflammatory lipid metabolism, and Lachnospiraceae_NK3A20_group to fatty acid and glycerophospholipid metabolism. RFT reprograms duodenal function through multi-level synergistic regulation involving microbial, metabolic, and transcriptional changes, thereby enhancing absorptive capacity and promoting subcutaneous fat deposition in Xizang sheep.