Effects of maternal wheat bran supplementation on microbiota and intestinal parameters of piglets

In pigs, new strategies to avoid infections at weaning focus on the impact of the maternal diet on the microbiota and intestinal health of piglets. In this study, the objective was to determine whether maternal dietary supplementation with wheat bran (WB) could modulate their piglets’ microbiota and enhance the health status at weaning. Eight sows were fed a high WB diet from day 43 of gestation (240g/kg DM of WB during gestation; 140g/kg DM during lactation) until weaning while 7 sows were fed a control (CON) diet devoid of WB. All diets were formulated to meet sows’ requirements and to be iso-nitrogenous and iso-energetic. Two days before weaning, the terminal ileum, caecum and colon contents of piglets were collected, the pH recorded and ileal tissues fixed in formaldehyde 4%. An ex vivo challenge was performed on colon tissues with or without lipopolysaccharide (from E. coli O111:B4) to observe immune responses. Microbiota of the colonic contents was determined by sequencing (Illumina MiSeq), short-chain fatty acids (SCFA) production by HPLC and histomorphological parameters after embedding in paraffin followed by haematoxylin-eosin coloration. All statistical analyses were performed in SAS, with the Kruskall-Wallis test (sequencing), the MIXED procedure (SCFA and pH) or the Nested procedure (histomorphology). Results showed differences between maternal treatments for microbiota of piglets, i.e. Colinsella, unclassified Clostridiaceae, Methanobrevibacter. For SCFA, piglets from WB sows showed decreased valerate molar ratio (MR) (p<0.05) in the terminal ileum, caecum and colon and the CON piglets showed higher butyrate MR in the caecum (13% for the CON piglets, 10% for the WB piglets; p=0.03). No impact of the maternal treatment was observed on the intestinal pH or histomorphological parameters. Results concerning the ex vivo challenge will also be presented. In conclusion, SCFA and microbiota were affected by the maternal treatment, and ex vivo results will allow to deepen the importance of these changes on the immune status of the piglets.