noun, plural: fibres
(4) (general) Any long strand of material
In nutrition, a dietary fiber may be soluble or insoluble. A soluble fiber is one that is commonly found in fruits and beans and water soluble. An insoluble fiber is one that is found in whole-grain products and vegetables. It is indigestible and therefore passes directly through the digestive system. The soluble dietary fiber is essential in improving glucose metabolism whereas the insoluble fiber helps in dealing with constipation.