In vitro evaluation of defined oligosaccharide fractions in an equine model of inflammation

Background Dietary supplementation with oligosaccharides has been proven to be beneficial for health in several mammalian species. Next to prebiotic effects resulting in a modulation of gut micro biota, immunomodulatory effects of oligosaccharides have been documented in vivo. Supplementation with defined oligosaccharide fractions has been shown to attenuate allergic responses and enhance defensive immune responses. Despite the accumulating evidence for immunomodulatory effects, very limited information is available regarding the direct mechanism of action of oligosaccharides. This study aims to elucidate the effects of selected oligosaccharide fractions on the lipopolysaccharide (LPS) induced inflammatory response in equine peripheral blood mononuclear cells (PBMCs). We investigated three different products containing either galacto-oligosaccharides (GOS) alone, a combination of GOS with fructo-oligosaccharides (FOS), and a triple combination of GOS and FOS with acidic oligosaccharides (AOS), at different concentrations. These products have been used in an identical composition in various previously published in vivo experiments. As the selected oligosaccharide fractions were derived from natural products, the fractions contained defined amounts of mono- and disaccharides and minor amounts of endotoxin, which was taken into account in the design of the study and the analysis of data. Acquired data were analysed in a Bayesian hierarchical linear regression model, accounting for variation between horses.