pig gut metagenome Metagenome

Besides the major nutrients, phosphorus is an essential nutrient for both the host animal and the porcine gut microbiota. Different strategies are used to enhance the phosphorus availability from cereals in pig diets, such as supplementation of phytase or soaking of cereals. The gut-lymph node axis is important with regards to the symbiotic relationship between gut microbiota and the host. However, little is known about the impact of diet-related bacterial shifts in the gut lumen on bacterial translocation into lymph nodes. Here, we characterized changes in the viable microbiota composition along the ileal digesta-mucosa-lymph node axis and examined the effect of dietary phytase supplementation and lactic acid (LA) soaking of cereals on the bacterial taxonomy along this axis together with their effect on the mucosal expression of innate immune and barrier function genes in pigs (n=8/diet). Thirty-two growing pigs (6-8 weeks old) were fed one of four wheat-corn-soybean meal-based diets according to a completely randomized design with 4 replicate batches: control diet (Con), diet with phytase (500 FTU/kg; ConP), diet containing lactic acid-treated cereals (Lac), and diet with phytase and lactic acid-treated cereals (LacP). Each experimental period lasted 19 days. On day 18 and 19 on the diet, ileal samples of digesta, mucosa and ileo-cecal lymph nodes were collected for total RNA isolation. After cDNA synthesis, the V3-V4 region of the 16S rRNA gene was sequenced on an Illumina MiSeq platform. Host gene expression was performed using RT-qPCR. Bioinformatics were performed in QIIME.