Biopolymers refers to natural polymers that are produces produced by cells of living organisms. Of particular interest to our group and nutritional sciences in general are carbohydrate polymers from plant sources such as starch, cell wall matrices (including non-starch polysaccharides or ‘dietary fibre’) and polyphenolics. Our research investigates the structure and properties of polysaccharides of biological and industrial interest, especially complex supramolecular bioassemblies found in plant foods. Currently, we study (a) the molecular mechanisms of α- amylase action on starch and starch-containing food matrices; (b) the role of cell walls in regulating nutrient bioaccessibility and gut function; and (c) the mechanisms by which plant cell wall polysaccharides (e.g. mixed linkage oat β-glucans, galactomannans) and plant phenolics can interact with intestinal secretions and endogenous biopolymers such as mucus. These physiological processes are important in regulating nutrient digestion and absorption and in understanding the factors that attenuate postprandial glycaemia, insulinaemia, gut hormones (e.g., GIP, GLP-1, PYY) and lipaemia.