the primary bile acid , chenodeoxycholic acid , and the secondary bile acid , deoxycholic acid , when present at a concentration of greater than 3 mm , induce salt and water secretion from the human colon and cause a marked increase in the permeability of the human colon to molecules of a molecular weight of 200-500 daltons .
C0008024
chenodeoxycholic acid
C0011479
deoxycholic acid