Dietary inclusion of arabinoxylan oligosaccharides (AXOS) down regulates mucosal responses to a bacterial challenge in a piglet model

Dietary oligosaccharides can influence the composition of the gut microbiota, and some are suggested to improve host resistance against infections. The exact mechanisms involved are largely unknown. The aim of the present study was to determine the response of the porcine small intestinal mucosa to feeding arabinoxylan oligosaccharides (AXOS), and whether it modulated the response to a single bacterial challenge with enterotoxigenic Escherichia coli (ETEC). Group pooled jejunal mRNA was analyzed by microarray. AXOS alone up regulated immune responses, and down regulated ETEC induced responses. Analysis of selected genes by qRT-PCR showed that AXOS had no effect on markers of epithelial differentiation and integrity whilst down regulating the epithelial marker intestinal fatty acid binding protein (IFABP). AXOS up regulates the inflammatory and antibacterial protein pancreatitis associated protein (PAP), independent of ETEC. It is concluded that AXOS may exert its attenuating effect on the ETEC induced small intestinal response by influencing the expression of particular innate response proteins such as PAP.

► Innate responses are important for disease resistance.
► Dietary oligosaccharides (OS) can possibly influence the innate immunity in the small intestine.
► Small intestinal responses to bacterial challenge were changed in arabinoxylan-OS fed piglets.
► Oligosaccharides have a direct effect on the small intestine in pigs and humans.