The extrusion process parameters (the moisture of wheat bran, temperature, and the rotating speed), were preliminarily optimized with orthogonal experimental design method. Fine wheat bran powder with a moisture content of 45 (w/w, %) was extruded by a laboratory scale twin-screw extruder (SYSLG32-II, Jinan Saibainuo Science and Technology Development Co, Ltd., Jinan, China) at a barrel temperature of 140 C at a rotation speed of 150 r/min. The extruded sample was then dried at 60 C in an oven for 48 h. Subsequently, the raw material was carefully ground into a fine powder using a mortar and pestle following pass through mesh screen (1 mm) and stored at 20 C. The contents of DF and SDF in the extruded wheat bran were determined by AOAC method.