Evaluation of Lactobacillus reuteri Pg4 strain expressing heterologous β-glucanase as a probiotic in poultry diets based on barley

The aim of this study was to evaluate the effectiveness of Lactobacillus reuteri Pg4 transformants (TLB) harbouring the heterologous β-glucanase gene as a probiotic supplement in a barley-based poultry diet. Four-hundred broiler chicks were allocated to two treatment groups with or without supplementation with 108 CFU/g TLB to investigate growth performance, digesta viscosity and intestinal microflora. Supplementation of the barley-based diet with TLB decreased digesta viscosity and improved body weight gain (P<0.05) of broilers from 0 to 37 days of age. Furthermore, a higher total anaerobic and Lactobacillus count was observed at 37 days of age in all segments of gastrointestinal tract of chicks fed TLB as compared to control chicks (P<0.05). Radial enzyme diffusion methodology was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of broilers fed TLB possessed β-glucanase secretion capability. The results indicate that the transformed strain survives transit through the stomach and intestine. In conclusion, the transformed Lactobacillus reuteri Pg4 can survive and secrete β-glucanase in the broiler GIT, and decrease digesta viscosity and enhance weight gain in birds fed a barley-based diet. Therefore, the transformed Lactobacillus reuteri Pg4 harbouring heterologous β-glucanase gene has potential as a poultry probiotic.