Endo-1,3(4)-beta-Glucanase-Treatment of Oat beta-Glucan Enhances Fermentability by Infant Fecal Microbiota, Stimulates Dectin-1 Activation and Attenuates Inflammatory Responses in Immature Dendritic Cells

Background: Non-digestible carbohydrates are added to infant formula to mimic the effects of human milk oligosaccharide by acting as prebiotics and stimulating the immune system. Although not yet used in infant formulas, beta-glucans are known to have beneficial health effects, and are therefore of potential interest for supplementation.Methods and results: We investigated the in vitro fermentation of native and endo-1,3(4)-beta-glucanase-treated oat beta-glucan using pooled fecal inocula of 2- and 8-week-old infants. While native oat beta-glucan was not utilized, both inocula specifically utilized oat beta-glucan oligomers containing beta(1 -> 4)-linkages formed upon enzyme treatment. The fermentation rate was highest in the fecal microbiota of 2-week-old infants, and correlated with a high lactate production. Fermentation of media supplemented with native and enzyme-treated oat beta-glucans increased the relative abundance ofEnterococcusand attenuated pro-inflammatory cytokine production (IL-1 beta, IL-6, TNF alpha) in immature dendritic cells. This attenuating effect was more pronounced after enzyme treatment. This attenuation might result from the enhanced ability of fermented oat beta-glucan to stimulate Dectin-1 receptors.Conclusion: Our findings demonstrate that endo-1,3(4)-beta-glucanase treatment enhances the fermentability of oat beta-glucan and attenuates pro-inflammatory responses. Hence, this study shows that especially enzyme-treated oat beta-glucans have a high potential for supplementation of infant formula.