Abstract：
To investigate the morphological changes of insoluble fiber and their effects on microbiota modulation, particularly Bacteroides, rice bran insoluble fibers were extruded at different feed moisture levels (E20, E40, and E60). The physicochemical properties and SEM revealed that E20 exhibited the highest water holding capacity and displayed the most fragmented edges. E40 had the highest swelling holding capacity and displayed the most lamellar gaps. E60 showed minimal change in physicochemical properties but had a rough surface. After 48h fermentation, E40 showed the highest levels of Bacteroides and SCFAs. E20 and E60 resulted in a modest increase in Bacteroides abundance. SEM showed that bacteria were attached to fragmented edges, loosened lamellar gaps, and rough surfaces of the extruded insoluble fibers. The results suggested that Bacteroides gained a competitive advantage within the extrusion treatment created structural changes. Extrusion treatment can be used to generate specific niches favorable for Bacteroides.
摘要：
探讨不溶性纤维的形态变化及其对微生物群调节的影响。特别是拟杆菌，在不同的饲料水分水平(E20、E40和E60)下挤出米糠不溶性纤维。理化性质和SEM显示E20表现出最高的持水能力，并显示出最破碎的边缘。E40具有最高的溶胀保持能力，并显示出最大的层状间隙。E60显示出物理化学性质的最小变化,但具有粗糙的表面。发酵48h后，E40显示出最高水平的拟杆菌和SCFA。E20和E60导致拟杆菌丰度的适度增加。SEM显示细菌附着在破碎的边缘，松散的层状间隙，和挤出的不溶性纤维的粗糙表面。结果表明，拟杆菌在挤出处理中获得了竞争优势，从而产生了结构变化。挤压处理可用于产生有利于拟杆菌的特定生态位。
