Effect of Oral Administration of Enterococcus faecium Ef1 on Innate Immunity of Sucking Piglets

The objective of this study was to evaluate the effect of orally administered Enterococcus faecium EF1 on innate immune responses of jejunal mucosa in newborn piglets. Twenty-four commercial crossbred healthy newborn piglets were randomly divided into two groups, control (T0) and treatment (T1) group. Each group consists of 12 piglets. T1 was administered sterilized skim milk 2 ml piglet-1 day-1 with addition of E. faecium EF1 (5~6×108 cfu/ml) by oral gavage on alternative odd days (1st, 3rd and 5th) after birth. T0 fed with the same volume of sterilized skim milk without probiotics. The merciful killing of piglets at the 25th day after birth was performed to collect the samples of jejunal mucosa to measure the innate cytokine responses and the Toll-like receptors gene expression by quantitative real time PCR. The results showed that TGF-β1 and TNF-α concentrations increased and mRNA expression levels also improved significantly in T1 as compared to T0. While, the production of IFN-γ and IL-8 decreased significantly in T1 and gene expression modification was not observed. In addition, TLR (Toll-like receptor) 2 and TLR 9 transcription levels were up-regulated in treatment (T1) group. These findings revealed that oral administration of E. faecium EF1 was effective to activate innate immunity and could modulate the TLRs expression in jejunal mucosa of piglets.