Short chain fatty acids (SFCA) are synthesized by the colonic microflora primarily from non-absorbed carbohydrate; there is also some limited production from non-absorbed protein. In contrast, SFCA are not normally present in the diet. During the past 15 years SFCA have attracted considerable interest in human nutrition, physiology and pathophysiology as a result of the realization that SFCA represent an important mechanism for carbohydrate and calorie conservation and may play a role in various types of colitides and possibly in colonic neoplasia. In addition, SFCA, produced in large amounts...