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 (1^st, 3^rd and 5^th) after birth. T₀ fed with the same volume of sterilized skim milk without probiotics. The merciful killing of piglets at the 25^th 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.

Key words: Cytokine, Enterococcus faecium, Piglets, Toll-like receptors