A Review on Dietary Fibres and Mechanism of Biological Action in Human Beings

Dietary fibre and whole grains contain a unique blend of bioactive components including resistant starches, vitamins, minerals, phytochemicals and antioxidants. As a result, research regarding their potential health benefits has received considerable attention in the last several decades. Epidemiological and clinical studies demonstrate that intake of dietary fibre and whole grain is inversely related to obesity, type-II diabetes, cancer and cardiovascular disease. Defining dietary fibre is a divergent process and is dependent on both nutrition and analytical concepts. The most common and accepted definition is based on nutritional physiology. Generally speaking, dietary fibre is the edible part of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine. Dietary fibre can be separated into many different fractions. Recent research has begun to isolate these components and determine if increasing their levels in a diet is beneficial to human health. These fractions include arabinoxylan, inulin, pectin, bran, cellulose, β-glucan and resistant starch. The study of these components may give us a better understanding of how and why dietary fibre may decrease the risk for certain diseases. The mechanisms behind the reported effects of dietary fibre on metabolic health are not well established. It is speculated to be a result of changes in intestinal viscosity, nutrient absorption, rate of passage, production of short chain fatty acids and production of gut hormones. Given the inconsistencies reported between studies this review will highlight the data concerning dietary fibre and its effects on metabolic health. Keywords: Dietary Fibre, Soluble Fibre, Insoluble Fibre, Human Health Biological Mechanisms, Gut Microbiota, Digestive Health