Dietary fiber,as the most important food source of the intestinal microbiota,maintains the balance and homeostasis of the microbiota.Its metabolites,short-chain fatty acids(SCFAs),play a very important role in improving energy metabolism,intestinal barrier function,immune system,inflammatory response and intes-tinal hormone secretion.However,the structural characteristics of dietary fiber and the composition and fer-mentation characteristics of fiber in different feed materials are quite different,which also leads to great varia-bility in the application of fibrous feed materials in animal production.Therefore,the structure and fermentation characteristics of dietary fiber were discussed in this paper,and the digestive process of dietary fiber compo-nents in animal intestines,the regulation mechanism of fermentation products on animal intestinal health,and the application status of dietary fiber in single-stomach animals were reviewed,aiming to provide reference for re-examining the fiber structure and its transport mechanism,and explore the potential nutritional value of dieta-ry fiber and formulating the application measures of fiber nutrition in monogastric animals.[Chinese Journal of Animal Nutrition,2024,36(4):2057-2066]