ABSTRACT
The short chain fatty acids (SCFA) — acetic, propionic, and butyric acid — are produced in the colon by fermentation of unabsorbed dietary carbohydrate. It has been demonstrated that SCFA are absorbed rapidly by the human jejunum, colon, and rectum. The in vitro incubation system has been used because of the very limited possibility of studying SCFA concentrations of relevant size such as in the portal vein in humans. SCFA activities and the processes whereby they are produced and absorbed need to be more thoroughly investigated and understood. Changes in the diet seem to be the most likely way of modifying the extent to which SCFA are produced and absorbed by humans and their impact on glucose and lipid metabolism. Data regarding the influence of dietary fiber on fecal SCFA in laboratory rodents, pigs, and non-human primates have been reviewed elsewhere.
