Soybean oil and leucine in late gestation and lactation improve maternal and offspring lipid metabolism and insulin sensitivity: insights from pig model

Introduction Lipid metabolism is crucial for the development of insulin resistance. Leucine supplementation enhances insulin sensitivity and lipid metabolism. Soybean oil has the potential to improve insulin sensitivity. A comprehensive investigation of the effects and potential mechanisms of leucine and soybean oil supplementation is warranted. This study aims to investigate the effects and underlying mechanisms of maternal soybean oil and leucine intake on lipid metabolism, insulin sensitivity in both dams and offspring. Materials and methods Sixty-eight multiparous sows (parities 3 to 5, 228.44 ± 8.19 kg) were randomly divided into four groups from the 107th day of gestation to the 21st day of lactation ( n = 17). The experimental was designed as a 2 × 2 factorial arrangement, which included the level of soybean oil (crude fat 5% or 10%) and leucine (0 or 1%) in the diet. Results Supplementing soybean oil during late pregnancy and lactation significantly enhanced insulin sensitivity ( P < 0.05). Both soybean oil and leucine altered the intestinal microbiota of sows, and significantly improved plasma lipid metabolism ( P < 0.05). Additionally, inflammation in sows before and after farrowing was reduced by lowering the relative abundance of pro-inflammatory bacterial genus such as Catenisphaera, Terrisporobacte and Peptococcus ( P < 0.05). The weaning weight of piglets was significantly increased ( P < 0.05), along with enhanced insulin sensitivity, increased immune ( IL10RA, DDX58 ), and improved lipid metabolism ( PPARA, SLC27A2 ) and rhythmic gene expression ( LGR4, KLF9 ). Discussion Our study provides evidence that dietary supplementation with soybean oil and leucine affects offspring growth by modulating lipid metabolism and insulin sensitivity in sows and pigs, and by altering intestinal microbiota.