Water-soluble fractions obtained by enzymatic treatment of wheat grains promote short chain fatty acids production by broiler cecal microbiota

The use of exogenous cell wall degrading enzymes to improve the nutritional values of cereal grains has increased during the last decades. In this study, products from enzymatic hydrolysis of wheat grain were isolated and their ability to induce short-chain fatty acids was investigated using in vitro fermentation with cecal microbiota. Water-soluble fractions were obtained following incubation without and with a multicomponent enzyme preparation (MEP) (2 mL/kg) containing essentially endoxylanase and endoglucanase activities. These were further fractionated by size exclusion chromatography into high molecular weight (HMw) and low molecular weight (LMw) sub-fractions. The MEP treatment increased the content in water-soluble arabinoxylan (AX) and decreased the degree of polymerization (DP) of the xylan-backbone. In vitro fermentation assays using broiler cecal content as inoculum demonstrated that low substituted AX with reduced molecular weight isolated after MEP treatment yielded higher concentrations of acetate and butyrate. This result indicates that cecal fermentation of enzymatic degradation products into short-chain fatty acids, particularly butyrate, is one of the important mechanisms of MEP action on wheat-based diets that can contribute to the improvement of intestinal health and animal performance.