Inflection in nutrient transporter genes leads to potential changes in small intestine histomorphology with improved nutrient retention in chicken under dietary synbiotic supplementation

Abstract

This study investigated the role of synbiotic supplementation on gut histomorphology, expression of nutrient transporters, and nutrient utilization in broiler chicken. Bacitracin methylene disalicylate (BMD), Probiotic Lactobacillus acidophilus (LBA), and prebiotic Mannan-oligosaccharides (MOS) were used to formulate total 6 dietary treatments viz. T1 (control; basal diet), T2 (BMD @ 20 mg/kg diet), T3/T4 (0.1% MOS with 106 and 107 cfu LBA/g diet), and T5/T6 (0.2% MOS with 106 and 107 cfu LBA/g diet). A total of 288 day old chicken were allocated at random among six treatments, each with six replicates of eight chicken (48 birds/treatment). Results revealed higher villus height, crypt depth, villus height: crypt depth ratio, and histological surface magnification ratio values in chicken fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet). BMD supplemented birds had higher values of these parameters compared to control birds. The villus width, villus bottom area, and mucosal unit bottom area were all increased in birds supplemented with BMD, but were similar to birds fed a combination of MOS (0.1 percent) and LBA (107 cfu/g diet). The villus width, villus bottom area, and mucosal unit bottom area were higher in BMD supplemented birds which were similar to the birds fed a combination of MOS (0.1%) and LBA (107 cfu/g diet). The birds fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet) revealed upregulation of SGLT1 and GLUT5 expression in jejunum but no significant effect was observed on the expression of PePT1 and EAAT3 gene. The AME Diet, nitrogen, phosphorus, and calcium retentions were higher in birds fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet). However, the organic matter digestibility was higher in birds fed a combination of MOS (0.2%) and LBA (106 cfu/g diet) and BMD supplementation also improved the organic matter utilization compared to control. In conclusion, the supplementation of a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet) improves the intestinal architecture along with upregulation of SGLT1 and GLUT5 nutrient transporters and increase in nutrient digestibility in broiler chicken.