Fibres differ....

Many people think that we should eat more fibre but they don't know why.There is the assumption that all fibre is the same.But some fibre lowers blood sugar and other fibres lower cholesterol& some for regularity. Those differences did not matter so much when all of our fibre was intact and unprocessed from foods like whole grains, beans, vegetables and fruits since usually has a mix of fibres.
Now companies are adding isolated fibres which are purely purified powders to frozen desserts, yogurts, juices, drinks and other foods that have always been fibre free-why? Nobody knows...