The effect of multi-strain probiotics as feed additives on performance, immunity, expression of nutrient transporter genes and gut morphometry in broiler chickens

OBJECTIVE: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens. METHODS: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T(1) (negative control-basal diet), T(2) (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T(3) (MSP at 10(7) colony-forming unit [CFU]/g feed), and T(4) (MSP at 10(8) CFU/g feed). RESULTS: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T(3) and T(4) groups. The feed intake significantly (p<0.05) reduced from T(1) to T(3) during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T(3) and T(4) during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T(3) and T(4). However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T(3) followed by T(4) and T(2). At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT1) and peptide transporter (PepT1) showed a significant (p<0.05) up-regulating pattern in T(2), T(3), and T(4). Whereas, at 21 d post hatch, the gene expression of SGLT1 and PepT1 was significantly (p<0.05) down-regulated in MSP supplemented treatments T(3) and T(4). CONCLUSION: The supplementation of MSP at 10(7) CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.