Effect of feeding isolated dietary fiber from M. paradisiaca on the metabolism of carbohydrates in the liver has been studied. Fiber fed rats showed significantly lower levels of fasting blood glucose and higher concentration of liver glycogen. Activity of glycogen phosphorylase, glucose-1-phosphate, uridyl transferase and glycogen synthase was significantly higher while phosphoglucomutase activity showed lower activity. Activity of some glycolytic enzymes, viz. hexokinase and pyruvic kinase was lower. Glucose-6-phosphatase showed higher activity while fructose 1-6 diphosphatase activity was not affected. Glucose-6-phosphate dehydrogenase on the other hand showed higher activity. The changes in these enzyme activities have been attributed due to the effect of higher concentration of bile acids produced in the liver as a result of feeding fiber. Evidence for this has been obtained by studying the in vitro effect of cholic acid and chenodeoxy cholic acid.