Modulation of piglet’s immune system development with fecal microbial transplantation

Abstract

Abstract The aim of the study was to investigate fecal microbial transplantation (FMT) as a novel strategy to modulate the postnatal development of porcine immune system and the establishment of the intestinal microbiota in newborn piglets. Ten litters were used for the experiment. At birth, four piglets were identified in each litter and randomly assigned to the control (CTRL) and the FMT groups. At 3,4,8,9, and 10 days of age, piglets in the FMT group were orally administered with FMT material suspended in 10% bovine colostrum solution. The FMT was prepared with an equal mixture of fecal material harvested from healthy suckling and fully weaned piglets. Control group was inoculated with the vehicle solution. Animals were then euthanized at d 22 to identify the leukocyte subsets in mesenteric lymph nodes (MLN) and blood by flow cytometry and to characterize the microbiota from ileum, caecum and colon by 16S rRNA amplicon sequencing. Results showed that FMT reduced the overall number of T lymphocytes (CD3+) both in blood and MLN (P<0.05). Blood percentages of Th lymphocytes (CD3+CD4+CD8α−) were also reduced in piglets receiving FMT (P<0.05), as well as γδ T lymphocyte (CD3+γδ+) and monocyte/macrophage (SWC3+CD14+) concentrations in the MLN (P<0.05). On the other hand, FMT increased the blood percentage of NK cells (CD3−CD4−CD8α+CD16+) (P<0.01). Results obtained from the microflora analysis confirmed that FMT administration affected piglet’s colon microbiota. In conclusion, although it had a mild impact on hindgut microflora, we observed that FMT has the potential to modulate the immune system development in newborn piglets. Further studies are necessary to fully understand the long-lasting effects of FMT on animal health.