Maternal fish oil supplementation enhances placental nutrient transport and mammary gland secretion via the GPR120 signaling pathway

Introduction

Maternal fish oil (FO) supplementation during pregnancy has been shown to improve pregnancy outcomes. FO is recognized as dietary source for n-3 polyunsaturated fatty acids (n-3 PUFAs). While early research has focused on the benefits of n-3 polyunsaturated fatty acids n-3 PUFAs for fetal neurodevelopment, retinal maturation and neonatal behavior, their roles in the placenta during late pregnancy and in the mammary gland during lactation still remain unknow.

Objectives

Here, we aim to clarify the mechanisms by which maternal supplementation with FO during pregnancy and lactation affects placental and mammary gland function.

Methods

We evaluated the effects of FO on maternal placental nutrient transport, mammary gland milk synthesis and offspring growth. We then explored the molecular mechanisms by which docosahexaenoic acid (DHA) affects the function of placental trophoblast cells and nutrient secretion of mammary epithelial cells through in vitro experiments. Finally, a lipopolysaccharide-challenged experiment was performed to access the potential of maternal FO supplementation in alleviating offspring intestinal inflammation.

Results

Maternal supplementation with FO during late pregnancy increased offspring birth weight, associated with enhanced maternal placental vascularization and nutrient transporter abundance. Additionally, maternal FO supplementation during lactation improved mammary gland secretion, increasing the fat, protein, and non-fat solids content in both colostrum and mature milk, thereby promoting offspring growth. The stimulatory effects of DHA on placental trophoblast cell function and nutrient secretion in mammary gland epithelial cells were mediated by GPR120 signaling pathways. Furthermore, maternal FO supplementation strengthened the placental barrier, reduced placental inflammation, oxidative stress and alleviated lipopolysaccharide-induced intestinal inflammation in offspring.

Conclusion

Maternal FO supplementation during late pregnancy and lactation enhances offspring growth by increasing placental nutrient transport and mammary gland secretion function, mediated by GPR120. Additionally, maternal FO supplementation reduces the susceptibility of offspring to intestinal inflammation.