Dietary fibers have been the subject of many researches since these are considered as one of those nutrients that can help in the promotion of health and at the same time can help in disease prevention. These researches have been validated by FDA when the government agency approved the claims that appear on most food labels that say that dietary fibers have a hand in the prevention of heart diseases and other form of cancers.

Another reason why dietary fibers have been the target of researches is that food scientists, nutritionists and medical persons are all optimizing the real definition of dietary fibers. Though there is an accepted definition that states dietary fibers as those fibers that are derived from the edible parts of plants that aren't broken down by the digestive system; this definition is still lacking and do not do justice on the real worth of dietary fibers. Researches, medical experts and nutritionists see this definition as lacking and ambiguous.

In order to optimize the definition of fibers, a new definition of fibers has been forwarded and this newer definition includes the physiological benefits of these nutrients. This new definition was forwarded by the American Association of Cereal Chemists. And it defines dietary fibers as nutrients that promote physiological effects that include laxation and blood control and glucose attenuation. The Institute of Medicine at the National Academy of Sciences has forwarded another definition as well and this time dietary fiber and fiber was differentiated.

Though the definition may vary from one organization to the other, the main role of dietary fibers in the body of humans cannot be denied. Dietary fibers are great help in the fight against a number of diseases like heart disease, colon cancer, diabetes and obesity. If taken in recommended amounts, dietary fibers are great help in reducing cholesterol levels in the body. The viscous fibers help lower the serum cholesterol and this is done by the reduction of the absorption of the dietary cholesterol. Also these viscous fibers partner with bile acids in order to digest fat the proper way.

Dietary fibers are also helpful in normalizing the blood sugar levels in the body. This is done by slowing the rate at which the eaten food leaves the stomach and by effectively delaying the absorption of the glucose after a meal. These fibers also increase the sensitivity of the insulin. And thanks to this role, the intake of dietary fibers help in the prevention and the treatment of type 2 diabetes.

The intake of dietary fibers can also help the person control his weight. These fibers promote a sense of fullness, thus a person can control his over-eating. The high intake of dietary fibers also helps in the promotion of bowel regularity.

There are certain types of fibers that are referred to as fermentable fibers and these are fermented by the bacteria that reside in the large intestine. The fermentation that happens effectively produces a short-chain of butyric acid and this acid serves as the primary fuel for the cells in the large intestine to maintain the health of the colon.