WHAT ARE DIETARY FIBRES?
Fibres are not a single food or substance. Fibre in itself has no calories because the body cannot absorb it. As it is carried through the digestive system and out the body, fibre maintains health and lowers the risk of number of diseases and conditions, including colorectal and other types of cancer. Plants are a unique source of dietary fibre because of the polysaccharide structure of the cell wall, as well as the storage and secretion polysaccharides associated with plant cells and seeds. Dietary fibre is clearly important for normal gastrointestinal function. This role is well defined in the large intestine, where dietary fibre provides bulk and the substrates for microbial activity. Several investigators have proposed that the adequacy of fibre intake can be determined by estimating the amount of fibre needed to maintain an adequate stool weight and transit time.
