Effects of acarbose in rats are influenced by the type of dietary starch

When rats consume a high cornstarch (raw) diet containing the alpha glucosidase inhibitor acarbose, they transport a large portion of the undigested starch into the large bowel, causing massive distention of the lower GI tract. In the present study we compare the effects of acarbose (50 mg per 100 g diet) when mixed in a raw cornstarch diet to its effects when mixed in a cooked cornstarch diet of otherwise identical composition. Controls received the respective diets but without the drug. In contrast to its effects when mixed in the raw cornstarch, mixed in the cooked cornstarch diet, acarbose consumption was not accompanied by any significant fecal losses of dietary starch. The intestinal distention induced by the drug was also much smaller in the rats eating the cooked cornstarch than the raw cornstarch. When either diet contained acarbose, fat depot weights were significantly lower than when the diets did not contain the drug. However, the difference was consistently greater with the raw cornstarch diet.