Chemical features and biological functions of water-insoluble dietary fiber in plant-based foods

Insoluble dietary fiber (IDF) is a nutritional component constituting the building block of plant cell walls. Our understanding of the role of IDF in plant-based foods has advanced dramatically in recent years. In this Review, we summarize research progress on the subtypes, structure, analysis, and extraction methods of IDF. The impact of different food processing methods on the properties of IDF is discussed. The role of gut microbiota in the health benefits of IDF is introduced. This review provides a better understanding of the chemical features and biological functions of IDF, which may promote the future application of IDF in functional food products. Further investigation of the mechanisms underlying the health benefits of IDF enables the development of effective strategies for the prevention and treatment of human diseases.