Effect of Dietary Lactitol on the Composition and Metabolic Activity of the Intestinal Microflora in the Pig and in Humans

1NTRODUCTION The metabolic activity of the digestive tract microflora has been recognised for many years and has been extensively re~iewed.~*~'~~* The many important products include ammonia (by amino acid deamination and urea hydrolysis), fatty acids (by amino acid deamination and carbohydrate fermentation), bile acid metabolites (by deconjugation and 7a-dehydroxylation of bile salts and bile acids), indoles (from tryptophan), volatile phenols (from tyrosine) and coprostanol (by reduction of the 5-6 double bond of cholesterol). Some of these metabolites are thought to be of importance in the causation of gallstones, colorectal cancer,14 hepatic coma25 and various other di~eases.'~ Thus modulation of the rate of formation of such microbial