Exogenous Enzymes Influenced Eimeria-Induced Changes in Cecal Fermentation Profile and Gene Expression of Nutrient Transporters in Broiler Chickens

Abstract

Two 21-day experiments were conducted to investigate the effects of exogenous enzymes on growth performance, tight junctions, and nutrient transporters, jejunal oligosaccharides and cecal short-chain fatty acids (SCFA) of broiler chickens challenged with mixed Eimeria. Two different basal diets: high fiber-adequate protein (HFAP; Expt. 1) or low fiber-low protein (LFLP; Expt. 2) were used in the two experiments. In each experiment, birds were allocated to four treatments in a 2 × 2 factorial arrangement (with or without protease and xylanase combination; with or without Eimeria challenge). In Expt. 1, with HFAP diets, Eimeria upregulated (p < 0.05) the expression of claudin-1, but downregulated (p < 0.05) glucose transporters GLUT2/GLUT5. On the contrary, enzymes downregulated (p < 0.05) claudin-1 and alleviated the Eimeria-depressed GLUT2/GLUT5 expression. In both experiments, Eimeria decreased (p < 0.05) cecal saccharolytic SCFA and increased (p < 0.05) cecal branched-chain fatty acids. The challenge × enzyme interaction (p < 0.05) showed that enzymes reversed the Eimeria effects on fermentation pattern shift. In conclusion, Eimeria altered tight junctions and nutrient transporters expression promoted cecal proteolytic fermentation and inhibited saccharolytic fermentation. Exogenous enzymes showed the potential of alleviating the Eimeria-induced intestinal gene expression changes and reversing the unfavorable cecal fermentation pattern.

The effects of xylo-oligosaccharides on regulating growth performance, nutrient utilization, gene expression of tight junctions, nutrient transporters, and cecal short chain fatty acids profile in Eimeria-challenged broiler chickens

“…The upregulation of GLUT1 may also be related to the host's strategy to transport more nutrients out of cells and lead to cell nutrient depletion and apoptosis. Additionally, a similar finding of downregulation of CAT2 and y+LAT2 with Eimeria infection has been previously reported ( Lin and Olukosi, 2021b ; Teng et al, 2021a ). However, the mechanism behind the observation is unclear.…”

“…The current experiment showed that the parasite challenge significantly upregulated gene expression of claudin-1 and JAM2. Similar changes in tight junctions have been reported in previous Eimeria challenge studies ( Lin and Olukosi, 2021a ; Teng et al, 2021b ). It has been demonstrated that upregulation of claudin-1 is elevated in inflammatory bowel disease conditions ( Poritz et al, 2011 ).…”

“…On the contrary, the Eimeria challenge decreased the concentration of saccharolytic SCFA including acetate, butyrate, and total SCFA, indicating a depression in carbohydrate fermentation. A similar SCFA pattern shift was observed in previous Eimeria challenge studies ( Lin and Olukosi, 2021a ). The increased BCFA can be explained by Eimeria -induced depression in N utilization (37.5% units’ reduction in the ileum).…”

“…After being vortexed and and allowed to settle for 5 min, the mixture's top layer was transferred to a glass vial and analyzed on gas chromatography. Dietary oligosaccharides profile was analyzed using matrix-assisted laser desorption ionization mass spectrometry detection as described previously ( Lin and Olukosi, 2021a , 2021b ).…”

“…Based on the prebiotic effects on modulating composition or activities of intestinal microflora, it is generally accepted that prebiotics have the capacity to alleviate pathogenic coccidia-induced negative effects, especially in ameliorating dysbacteriosis which is the typical symptom of coccidiosis ( Baurhoo et al, 2007 ; Mookiah et al, 2014 ; Abd El-Hack et al, 2021 ). In addition, carbohydrate fermentation stimulated by prebiotics acidify the cecal environment which mitigates adverse effects of Eimeria infection on cecal fermentation ( Adhikari and Kim, 2017 ; Lin and Olukosi, 2021a ).…”