This study determined the potential of formic acid plus monolaurin (FA + ML) as an alternative to antibiotics in diet when piglets are challenged with ETEC. Piglets fed the FA + ML diet had lower fecal score and rectal temperature after the ETEC challenge. In addition, FA + ML supplementation induced lower plasma TNF-α, IL-6, and IL-1β concentration postchallenge, downregulated the mRNA expression of TNF-α, IL-1β, IL-6, and TLR4 in the ileum and TLR4 and CFTR in the jejunum. Phosphorylation levels of NF-κB p65 and MAPK p38 were reduced in the ileum of piglets fed FA + ML diet. Supplementation of FA + ML increased the relative abundance of genera Lactobacillus especially Lactobacillus amylovorus species and decreased the genus abundances of Actinobacillus, unidentified Enterobacteriaceae, Moraxella. Collectively, the combination of formic acid and monolaurin in diets have the potential to be an antibiotic alternative to mitigate inflammatory response in piglets challenged with ETEC.
Keywords: Escherichia coli; formic acid; monolaurin; piglets.