Question

“Dietary fiber is indigestible in the human digestive tract”, comment on the statement.

Answer 1

Dietary fiber is made of cellulose, and provides “inert mass” to the food while it is moving down the digestive track. However, the enzymes and acid present in our digestive system does not impact the breakdown of complex cellulosic fiber. Think of it as a cotton ball that traverses through your digestive track, sweeping out and removing any detritus that remains stuck to the walls or inaccessible places in your intestines.

So, dietary fiber plays a key role in keeping you healthy, but it does not get broken down by the digestive juices and enzymes.

Farm animals (herbivores in general) have a much more elaborate and complicated digestive process, and they maintain a more diverse microbiome (bacteria in the digestive track) as compared to humans. They have bacteria in their gut that are capable of feeding on cellulose and breaking it down into smaller units that are more easily digested. Therefore, herbivores and omnivores have the capability to digest complex cellulose substrates (e.g. grass and leaves) whereas humans do not.

Answer 2

In cows there is a special kind of bacteria in the stomach, Rumino coccus which break down fibre like cellulose into Acetic acid , Butyric acid and Proptonic acid by producing cellulase.but in case of human beings no such enzyme is produced in the stomach and that is why humans are not able to digest cellulose and oher fibres.