The contribution of the large intestine to energy supplies in man.

Herbivores obtain a considerable proportion of energy requirements from carbohydrate by the chain of anaerobic carbohydrate fermentation producing short-chain fatty acids that are absorbed then metabolized. The evidence for this sequence occurring in the large intestine of man is reviewed and estimated to produce 5 to 10% of human energy requirements. Further small amounts of energy may come from large intestinal absorption of fat and the bacterial breakdown products of protein.