Lipid metabolism is very important for meat quality in pigs. Accumulating evidence shows that gut microbiota can contribute to this physiological process. However, the gut microbiota that function in lipid metabolism and adipogenesis remains unclear. Here, we compared the characteristics of fat deposition and gut microbial community between Laiwu pigs and Duroc × (Landrace × Yorkshire) (DLY) pigs. Fecal microbiota transplantation (FMT) was performed to determine the possible impact of gut microbiota on lipid metabolism in pigs. An integrated analysis of the gut microbiome and lipidome of the small intestine, plasma, and liver was conducted to investigate the effects of FMT on host lipid metabolism. The comparative analysis of the gut microbiome showed higher abundance of Bacteroidetes (P = 0.0018) while lower abundance of Firmicutes (P = 0.012) in Laiwu pigs, and the microbial composition can be transferred from Laiwu pigs into DLY pigs. Transmission electron microscope and Oil red-O staining were performed to analyze the effects of FMT on lipid deposition in liver, the main target organ for lipid metabolism. The results showed that FMT significantly increased the number of lipid droplets (P = 0.0035) and lipid accumulation (P = 0.0026) in liver. Furthermore, integrated multi-tissues lipidome analysis demonstrated that the fatty acyls and glycerophospholipids were significantly increased (P < 0.01) in intestine and liver, while glycerolipids and fatty acyls were reduced (P < 0.01) in plasma. In the small intestine, FMT increased (P < 0.01) the relative abundance of polyketides and prenol lipids but reduced (P < 0.01) the saccharolipids. Correlation analysis revealed the potential interactions between microbiota and lipid metabolites. Together, our results indicated that the gut microbiota may regulate the lipid metabolism and enhance the accumulation of lipid droplets in the liver of pigs.

脂质代谢对猪的肉质非常重要。越来越多的证据表明，肠道微生物群可以促进这一生理过程。然而，在脂质代谢和脂肪生成中起作用的肠道微生物群仍不清楚。在这里，我们比较了莱芜猪和杜洛克×（长白×约克郡）（DLY）猪的脂肪沉积和肠道微生物群落特征。进行粪便微生物群移植 (FMT) 以确定肠道微生物群对猪脂质代谢的可能影响。对小肠、血浆和肝脏的肠道微生物组和脂质组进行了综合分析，以研究 FMT 对宿主脂质代谢的影响。肠道微生物组的比较分析显示拟杆菌的丰度更高（P = 0.0018) 而莱芜猪厚壁菌门 ( P  = 0.012) 的丰度较低，微生物组成可以从莱芜猪转移到 DLY 猪中。采用透射电镜和油红-O染色分析FMT对脂质代谢的主要靶器官肝脏脂质沉积的影响。结果表明，FMT显着增加了肝脏中的脂滴数量（P  = 0.0035）和脂质积累（P  = 0.0026）。此外，综合多组织脂质组分析表明，肠道和肝脏中的脂肪酰基和甘油磷脂显着增加（P  <0.01），而甘油脂和脂肪酰基减少（P < 0.01) 在血浆中。在小肠中，FMT 增加了 ( P  < 0.01) 聚酮化合物和异戊烯醇脂质的相对丰度，但减少了 ( P  < 0.01) 糖脂。相关性分析揭示了微生物群和脂质代谢物之间的潜在相互作用。总之，我们的研究结果表明，肠道微生物群可以调节脂质代谢并增强猪肝脏中脂滴的积累。