Nutrient transporters and tight junction expression and cecal short-chain fatty acid profile in Eimeria-challenged broilers fed diets with different levels of xylo-oligosaccharides

A total of 252 Cobb 500 male broiler chicks were used in a 21-d experiment to study the possibility of xylo-oligosaccharides (XOS) helping to recover gut impairment in Eimeria-challenged broilers by regulating the expression of nutrient transporters and tight junctions, and cecal short-chain fatty acids (SCFA), which is an indicator of bacterial status. Birds were allocated to 6 treatments in a 3 × 2 factorial arrangement (3 corn-soybean diets with 0, 0.5, 1 g/kg XOS × with or without Eimeria challenge). Each treatment had 6 replicates with 7 birds per replicate. Challenged groups were inoculated with a solution containing E. maxima, E. tenella, and E. acervulina oocysts on d 15. On d 21, jejunal tissue was collected for gene expression analysis and cecal content was collected for SCFA analysis. The Eimeria × XOS interaction for tight junction claudin 1 showed that both 0.5 and 1 g/kg XOS alleviated (P < 0.05) Eimeria-induced claudin 1 upregulation. The Eimeria × XOS interaction for sugar transporters showed the extent of Eimeria-induced GLUT2 and GLUT5 downregulation was smallest in the 0.5 g/kg XOS supplemental treatment. In addition, Eimeria upregulated (P < 0.01) tight junction JAM2 and glucose transporter GLUT1 but downregulated (P < 0.01) the peptide transporter PepT1, amino acid transporters rBAT, CAT2, y+LAT2, and zinc transporter ZnT1. Eimeria decreased (P < 0.05) cecal saccharolytic SCFA acetate, butyrate and total SCFA, but increased (P < 0.05) cecal branched-chain fatty acids isobutyrate and isovalerate. The supplementation of XOS tended to decrease the concentration of isobutyrate (P = 0.080) and isovalerate (P= 0.062). In conclusion, Eimeria challenge triggered changes in expression of tight junction and nutrient transporter genes. Supplemental XOS helped reverse the gene expression changes in tight junction claudin 1 and glucose transporter GLUT2 and GLUT5, and showed the potential of alleviating the Eimeria-induced unfavorable cecal fermentation pattern.

Key Words: xylo-oligosaccharides, Eimeria, tight junction, nutrient transporter, short-chain fatty acids (SCFA).

Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.