Fibre plays an essential role in health and well-being but modern diets frequently contain insufficient fibre. Plant origin fibre is indigestible but essential for good intestinal transit. A residue and constituent of plant cell walls, fibre comprises a complex mix of carbohydrates known as non-starch polysaccharides. Undigested by the body, fibre passes intact through the digestive tract until it arrives at the large intestine. Soluble fibre helps regulate blood sugar and cholesterol levels. It increases bacterial activity in the colon and when it is broken down by bacteria, substances are produced that stimulate contraction of the intestine promoting easier elimination of stools from the body. Insoluble fibre retains water, speeds up intestinal activity, reduces transit time and encourages regular motions. By decreasing transit time, it also helps restrict the amount of toxins that can be absorbed. Fibre is a valuable aid to weight loss as it regulates absorption of carbohydrates and fats. It also has a beneficial effect on satiety - by absorbing water in the stomach and swelling, it reduces appetite.