The Role of Carbohydrates in Lower Gut Function

Autor: Hans N. Englyst, John H. Cummings, H. S. Wiggins
Rok vydání: 2009
Předmět:
Zdroj: Nutrition Reviews. 44:50-54
ISSN: 1753-4887
0029-6643
DOI: 10.1111/j.1753-4887.1986.tb07586.x
Popis: Few students of human digestive physiology regard the large intestine as anything other than an organ that salvages some of the salt and water which escape absorption in the small bowel. However, in monogastric species such as the horse, pig, rabbit, and rat, the large bowel plays an essential role in digestion and absorption, providing up to one third of the animal's daily energy requirements together with a variety of other nutrients including trace elements and vitamins. The large bowel may be equally important in human beings, but it is relatively inaccessible for study, and has not attracted much interest because the diets eaten in most industrialized countries do not require a colonic phase in their digestion. Fermentation is probably the principal function of the large intestine. The colon provides a suitable environment for the slow breakdown of many of the complex carbohydrates that are present in diets high in plant material. The main products of this carbohydrate fermentation are short-chain fatty acids and various gases (H,, CO,, CH,). The bacteria also obtain energy from this process for growth and for maintenance of cellular function. Short-chain fatty- acids are rapidly absorbed from the human colon1 while the gases are excreted through the rectum or in the breath. The fate of carbohydrate broken down in the colon is thus in marked contrast to that which is digested in the small intestine (Figure 1). Carbohydrate is rapidly hydrolyzed in the small bowel by a com
Databáze: OpenAIRE
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