BAY-e 4609, an -amylase inhibitor of microbial origin, was characterized to be of carbohydrate nature and showed a significantly higher inhibitory potency. However, also this compound demonstrated only modest efficacy in clinical trials. Because -amylase inhibitors affect only starch digestion, the degradation of important oligo- and disaccharides by the membrane bound enzymes is not inhibited, the overall efficacy is only modest.