Hydrocolloids in the digestive tract and related health implications

Hydrocolloids in the form of polymeric ingredients as well as natural biopolymer assemblies provide much of the macroscopic structure of foods. The controlled disassembly of hydrocolloid-structured foods in the digestive tract determines numerous nutritional properties driven by the rates of passage, digestion, absorption, and fermentation. Despite convincing evidence for health benefits of hydrocolloids (particularly dietary fibre) from epidemiology, and numerous in vitro model system studies, the detailed underlying mechanisms operating in the digestive tract are currently understood to only a limited extent. Distinct hydrocolloid-based processes occur in each of the gastric, small intestinal and large intestinal environments, with significant biological cross-talk between the sites. Hydrocolloids offer a major opportunity to tailor nutritional value and provide potential health benefits through control of gastric emptying and ileal brake mechanisms (satiety and potentially obesity), glycemic response (diabetes), plasma cholesterol levels (cardiovascular disease), and carbohydrate fermentation throughout the large intestine (colon cancer). There is often a parallel between the functionality of the plant-based foods which the human digestive tract evolved to digest and the use of extracted hydrocolloids in modern food structuring technology.