Aspects of dietary fibre in health and diseases

Abstract

Dietary fibre is the name collectively given to the indigestible carbohydrates present in foods. These carbohydrates consist of cellulose, gum, pectin and mucilage. Enzymes of gastro-intestinal tracts in humans do not digest these fibres. Plants are the only source of dietary fibre. It is found in grains, vegetables and fruits. Dietary fibre helps to keep the digestive system healthy, and it is vital in reducing the risk of diseases such as coronary heart disease, diabetes, diverticulosis, haemorrhoids and intestinal cancer. Undigested fibres enter the large intestine where bacteria ferments them. Carbon dioxide, nitrogen, hydrogen and short-chain fatty acids are the by-products of the fermentation. Soluble fibre and resistant starch also serve as prebiotic and supports the necessary probiotic for digestive health. In grapes, peas, beans and barley, much of the soluble fibre is extracted. When dissolved in the water, a gellike substance is formed. Soluble fibre helps to support the growth of friendly bacteria needed to maintain a healthy intestinal system. They also help in slowing down the time taken by the food to pass through the stomach into the small intestine, which helps to slow down the absorption of glucose and controls the blood sugar levels and helps in managing diabetes mellitus and keeps you feeling fuller for a longer time. The diets with high fibre intakes are known to have beneficial health effects as they have water holding capacity, helps in adsorption of organic molecules and facilitates its excretion, hypoglycemic effects and hypercholesterolemic effect. The inclusion of fibre rich food in weight-reducing diets is found to helpful since it provides a feeling of fullness without consumption of excess calories. The present review discusses the definition, nutritional properties of dietary fibre and therapeutic functions of dietary fibres in health and diseases.