Dietary Supplementation With Oil and Leucine Enhance the Gut Microbiota and Barrier of Offspring During Late Gestation and Lactation of Sows.

The interaction effects of leucine and oils on piglets' intestinal flora and barrier function are unclear. The objective of this study was to examine the impact of administering leucine and oil to pregnant sows on offspring intestinal well-being. At 107 days of gestation, 68 sows were randomly divided into four dietary treatments: a basal diet, a basal diet with 1% leucine, an oil-replenished diet (5.2% soybean oil), and an oil-replenished diet with 1% leucine. Piglets were sampled at the end of lactation. Results showed that maternal supplementation with leucine and oil significantly improved intestinal morphogenesis. The treatments significantly reduced malondialdehyde (MDA) levels and enhanced intestinal antioxidant status. Leucine upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and downregulated Kelch-like ECH-associated protein 1 (Keap1), thereby improving the Nrf2 signalling pathway. It also decreased the expression of nuclear factor kappa B (NF-κB) subunits (NF-κB1 and NF-κB2), downregulating the transcription of oxidative-related genes. Furthermore, oil and leucine enriched beneficial gut bacteria, leading to synergistically higher levels of short-chain fatty acids (SCFAs). Maternal dietary supplementation with soybean oil and leucine during late gestation and lactation exerts a profound, synergistic impact on the offspring's intestinal health. This integrated strategy provides theoretical support and a practical nutritional approach for precision management in pig farming.