Fibres

What is it?

Fibres are made up of indigestible parts of plants. They are complex carbohydrates which pass unchanged (and unabsorbed) through our stomach and small intestines, as the human digestive system does not possess the enzymes needed to break apart the links between carbohydrate units in fibres. Some fibres are partially or completed fermented by the gut microbia inhabiting the large intestine. Depending on their characteristics (soluble or not, fermentable or not), fibres will modify in a different way the gut environment and it is generally recommended to eat different types of fibres to benefit from them all.

The starch industry’s fibres are principally made from wheat and maize.

Where and Why is it used?

There are two major types of fibres: soluble and insoluble fibres. Soluble fibres dissolve in water and can form a viscous or gel-like material. They can help lower blood cholesterol and glucose levels. Soluble fibres can be found for example in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium. Insoluble fibres promote the transit of material through the digestive system. Whole-wheat flour, wheat bran and vegetables, such as potatoes, are good sources of insoluble fibres.

Both soluble and insoluble fibres can be found naturally in plant foods, e.g. in cereals, peas, beans, apples, citrus fruits, carrots, etc.  Meat, dairy products, eggs, and oils do not contain any naturally occurring fibres.

For adults, the recommended amounts of dietary fibre for promotion of adequate gut transit and better regulation of blood glucose range from 25 to 30 grams/day in adults. This level of intake is unfortunately not reached in many countries