Short chain fatty acids in the human colon

Abstract

There are close parallels between the fermentative processes which go on in the rumen, caecum, and colon of herbivorous animals and colonic metabolism in man. Short chain fatty acids, which are the main end-product of carbohydrate breakdown in these organs, exert a controlling influence on intraluminal events, absorption, mucosal metabolism, and are accepted as such by animal physiologists. Such recognition has yet to be given to this aspect of colonic function in man, and many studies of colonic metabolism have failed to take account of the possible effect of short chain fatty acids. A great deal still needs to be learnt about these acids in the human colon - in particular, the overall amount produced each day, the main substrates for fermentation, the effect of diet, the molecular form in which they are absorbed, their contribution to energy metabolism, and their interaction with a wide range of other colonic events. Such knowledge should yield important information which may be relevant to the aetiology of colonic disorders which are so prevalent in the human species.