Differences in Enzymatic Activities of Cecal Contents of Rats Fed on Differently Processed Dietary Fibers

Enzymatic activities in cecal contents were studied on rats fed on high cholesterol diets with ferulic acid arabinoxylan ester (FAX) and arabinoxylan (AX); both were processed from refined corn bran (RCB) and were compared with those of cellulose(CE)- and RCB-fed rats. The enzymatic activities in the ceca changed according to the diets. Xylanase activity, arabinofuranosidase activity and ferulic acid esterase activity appeared in the cecum of the FAX- and AX-fed rats, but these activities were not observed in the cecum of CE- and RCB-fed rats. FAX and AX showed a tendency to decrease serum cholesterol levels. At first, xylanase and arabinofuranosidase were supposed to attack the FAX and AX main chain and side chain, and thus high molecular weight FAX and AX became lower molecular weight fragments. At that time, ferulic acid esterase was presumed to attack and FAX was degraded lower. These enzymes might act synergistically.