Probiotic Administration Modulates the Expression of TLR in Goat Blood.

The objective of this study was to evaluate the effect of probiotics (FASTtrack microbial pack) on the expression of Toll-like receptors (TLR) in goats. Probiotics are viable microorganisms that have positive effects on growth performance, nutrient synthesis, the microbial ecosystem, absorption, and the reduction in the incidence of intestinal infection and restoration of gut microflora. Following initial screening for infection, one-week post weaning, female SpanishXBoer goats were drenched daily with the recommended doses of probiotic (containing Lactobacillus acidophilus, Saccharomyces cerevisae, Enterococcus faecium, Aspergillus oryza and fructooligosacharide) in 10 mL sterile water over an 8-week period. The control group was given sterile water. Blood samples were collected weekly. Total RNA was isolated from blood collected at the beginning of the study (week 0) and at the end of the study (week 8) using Tri-reagent. RNA integrity number (RIN) was determined with a Bioanalyzer and samples with RIN >7 for each treatment was reverse-transcribed to cDNA using the Ambion-Retroscript kit. The RT² profiler array was used to determine the expression of 84 genes involved in Innate and Adaptive Immunity. Fold change was calculated using the Livak method with GAPDH as the reference gene for normalization. At week 0, out of the 84 genes assayed, animals in the control group expressed 25 genes while 22 genes were expressed at week 8. In the treatment group, out of the 84 genes assayed in the treatment group, 41 genes were expressed at week 0, while 67 genes were expressed at week 8. Probiotict induced the expression of TLR3 and TLR8, and increased the expression of TLR4 (FC=27), TLR6 (FC=2), TLR7 (FC=7) and TLR9 (FC=3). Treatment with probiotics resulted in differential expression of genes related TLR signaling pathway. The results from this study will help in the definition of the role of TLR expression in goat blood, design of therapeutic probiotics and help define the mechanism of action of probiotics.