Effect of a Potential Probiotic Candidate Enterococcus faecalis-1 on Growth Performance, Intestinal Microbiota, and Immune Response of Commercial Broiler Chickens.

The probiotic effect of Enterococcus faecalis-1 (isolated from healthy chickens) on growth performance, immune response, and modulation of the intestinal microbiota of broilers was assessed with a total of 100-day-old commercial Cobb chicks. The chicks were randomly divided into two equal groups. The control group received a basal diet, while the test group received a basal diet and was orally supplied with E. faecalis at a dose of 108 CFU/bird/day. Results showed that E. faecalis-1 supplement significantly (P < 0.05) improved the body weight and feed conversion ratio of treated broilers compared with the control ones. The mortality percentage was reduced in E. faecalis-1-supplemented group. The total IgY serum level was significantly (P < 0.05) increased in broilers receiving E. faecalis-1 supplement (7.1 ± 0.39) compared with the control group (5.8 ± 0.3), while the serum avidin level was significantly (P < 0.05) decreased in E. faecalis-1-supplemented broilers (76 ± 11.1). There was no significant change in the immune response towards avian influenza and Newcastle vaccines in both groups. The total Lactobacillus and Enterococcus counts were significantly (P < 0.05) higher in the cecal contents of broilers given E. faecalis-1 than those that received the control treatment. E. faecalis-1 supplement enhanced the enzyme activities, antioxidant system, and liver functions of treated broilers compared with those in the control group. Collectively, these results showed that E. faecalis-1 could promote growth performance and immunological status and convey beneficial modulation of the cecal microbiota in broilers.

Endotoxin transiently inhibits protein synthesis through Akt and MAPK mediating pathways in C2C12 myotubes.

In this study, the effect of lipopolysaccharide (LPS) on protein synthesis (PS) and intracellular signaling factors that regulate it have been investigated in C2C12 murine-derived myotubes. In particular, the role of Akt/mammalian target of rapamycin (mTOR) and the mitogen-activated protein kinases (MAPKs) [p38 and extracelluar regulated protein kinase (ERK1/2)] have been examined. The direct effect of LPS on PS was measured at 3 and 18 h. LPS significantly decreased PS at 3 h but not at the 18-h time point. This effect was preceded by decreased Akt phosphorylation at 5 and 30 min after LPS administration. The mTOR phosphorylation exhibited a long time dose-dependent increase at all the time points. Similarly, the activity-related phosphorylation of p38 and ERK1/2 significantly increased in a time- and dose-dependent manner at all the time points. Polymyxin B abolished the LPS-induced decrease in PS rate. The phosphatidylinositol 3-kinase inhibitor LY-0294002 in combination with LPS significantly decreased the rate of PS by 81% and alone by 66%, respectively, for the 3- and 18-h time points, whereas p38 and ERK inhibitors in combination with LPS significantly decreased the rate PS rate at the 18-h time point by 41% and 59%, respectively, compared with control cells. In conclusion, LPS alone transiently decreased the rate of PS by 50% at 3 h; this effect is most likely mediated via the Toll-like receptor 4 (TLR4)-Akt/mTOR pathway, and both p38 and ERK when inhibited in the presence of LPS at 3 h have a similar effect in preventing the LPS-induced reduction in PS.