Low weight piglets show differences in intestinal microbiota, intestinal transcriptome and immune cell profile compared to high weight piglets during the first two weeks of lactation

Abstract

Abstract Piglets born with lower weight and showing low performances during the first weeks of lactation are associated with higher risks of gastroenteric diseases after weaning. Therefore, we investigated the developmental differences between these pigs compared to the high weight piglets. Eight litters adjusted to 12 piglets were used. In each litter, piglets showing the lowest weight gain (LWG) or the highest weight gain (HWG)in the first week of life were selected. For each piglets enrolled, ileal gene expression, immune cell populations and microbiota profiles were studied. Results obtained from microarray and Q-PCR analysis showed that, at 16 days of age, the expression of genes involved in oxidative stress and immune response was altered in LWG piglets’ ileum. Analysis of the LH-PCR data of the microbiota using non-metric multidimensional scaling (NMS) and blocked multiresponse permutation procedure (MRBP) revealed that the microbiota of the HWG and LWG piglets tended to differ in ileal mucosa (p = .097) and differed incolonic lumen (p = .024). From day 8 to 16, LWG piglets failed to show an increase of CD21+ B cells in their blood (P weight × day = 0.01), but showed an increase of CD4+CD8α-Th cells (P = 0.002), unlike the HWG piglets. Percentages of CD14+ monocytes and other MHC-II+ cells were respectively higher and lower on day 8 compared to day 16 (P < 0.01). Moreover, LPS activated PBMC from LWG piglets produced less IL-6 (P < 0.05). These results suggest that piglets low performances during lactation affect the development of their immune system and is associated with differences in intestinal gene expression profile and microbiota.