Globally, cereal grains are a staple part of the diet providing primarily carbohydrates and other phytochemical components. Detailed coverage of the composition and functionality of the bulk carbohydrate components, specifically starch, beta-glucans, and arabinoxylans, and the trace phytochemical components, i.e. phenolic compounds such as phenolic acids, anthocyanins, deoxyanthocyanins, and proanthocyanidins in cereal grains and grain products is provided. Considerable attention is paid to the interactions between carbohydrate and non-carbohydrate components in grains including starch–protein and starch–lipid interactions and their effects on starch digestibility. The phenolic constituents bound to grain dietary fiber also receive detailed consideration and the final chapter presents a review that discusses whole grain–gut microbiota interactions identifying new areas of research that may contribute to a better understanding of the underlying mechanisms linked to human health. This book provides researchers, clinicians and students with a comprehensive compendium on aspects of whole grain components and brings the literature up to date.