An Ovine Intestinal Organoid–Macrophage Co-Culture Model to Test the Effects of Ovine Colostrum Exosomes on Intestinal Barrier Function and Inflammation

Ovine colostrum exosomes obtained from nutritionally programmed dairy ewes (F0) may present modifications in microRNAs, thus having consequences for the intestinal barrier function and immunity parameters of lambs (F1). To test this hypothesis, colostrum exosomes from two ewe groups [F0-MET (nutritionally programmed ewes being fed methionine during early life) and F0-CTRL (ewes not supplemented with methionine during early life)] were sequenced to compare differences in the miRNAome. In addition, these exosomes were added to an in vitro co-culture in a Transwell chamber system consisting of ovine duodenum intestinal organoids and macrophages to assess the expression of genes encoding tight junction proteins in organoids and immunity parameters in macrophages. Finally, the concentrations of cytokines (e.g., IL-12 and IL-6) were assessed by ELISA kits in the supernatants of the chamber containing macrophages. According to the miRNAome, the expression of two miRNAs (e.g., oar_miR_376c_3p and oar_miR_432) was reduced in the colostrum exosomes obtained from dairy ewes nutritionally programmed with dietary supplementation of methionine during early life (F0-MET ewes). These changes did not seem to modify the expression of intestinal barrier and immune response marker genes when these exosomes were added to a co-culture of ovine intestinal organoids and macrophages. However, the levels of IL-12 produced by macrophages were reduced (<i>p</i> < 0.05), which suggests the inhibition of inflammatory pathways. Further studies using ovine colostrum exosomes obtained from nutritionally programmed ewes will help to clarify their potential to improve the health of suckling lambs.