Types of fibre

Insoluble fibres are the fibrous structural material of plant cell walls and have a low water holding capacity. Fermentation of the fibres is slow or does occur at all. Included are cellulose (from vegetables such as celery, legumes, fruit and nuts), lignin (found in wholegrain wheat, wholegrain oats, rye meal, brown rice. flaxseed seeds, pumpkin seeds, caraway seeds, sunflower seeds and the seeds of berries) and some hemi-celluloses (in cereals, fruit, legumes, vegetables and nuts)

Soluble fibres are the plant cell contents and have a high water holding capacity. They are fermented by microbes found in the intestine. They include beta-glucans, gums, mucillages, some semi-celluloses and pectin. Rich sources include legumes, fruit (especially apricots, bananas, cherries, figs, grapefruit and plums), oats, oat bran, rye, barley and psyllium.

Resistant starch is part of starch that passes undigested into the large intestine and is digested by microbes found there. Found in legumes, bananas, cooled cooked potato, al dente psata, corflakes and products made with Hi Maize.

Fructans contain a link between molecules which resists digestion in the small intestine but are digested by microbes in the large intestine. Examples are inulin and oligofructose. They are found in some vegetables ( onions, garlic and chicory) and grains (wheat) or may be added by some processed foods such as yoghurt.

How much fibre should I eat in a day?
25-35g of fibre daily is recommended for adults. During an attack of diverticulitis it is recommended that this be dropped to 5g per day and gradually increased after resting the bowel.

The average Australian currently eats about 15g of fibre per day.