Effect of dietary fiber on growth rate, jejunal mucosa activity and its morphology of rats fed tween 60 and sodium deoxycholate

The mechanism by which Tween 60 (polyoxyethylene sorbitan monostearate) and sodium deoxycholate (DOC) exert adverse effects on gastrointestinal functions, food intake and growth rate were studied. The protective effect of dietary fiber prepared from gobo (GDF) against these surface active agents were also studied. In homogenated jejunal mucosa, sucrase activity was significantly inhibited in the presence of 1.5% Tween 60, whereas glycyl-L-leucine hydrolase activity was not affected. The activity of the latter enzyme was markedly inhibited in the presence of 0.038% DOC. Unlike Tween 60 (1.5%), a perfusion of DOC (0.038%) together with 100mM glucose through the rat jejunum significantly reduced glucose absorption from the perfusate. The addition of Tween 60 (15%) to the purified basal diet caused diarrhea and a significant decrease in food intake and growth rate. The adverse effects of this diet were completely counteracted by a supplement of 5% GDF. When daily feed consumption of the basal diet group was adjusted to the same amount as that of the group fed ad libitum the Tween 60-containing diet, there was no significant difference in growth rate between both groups. Therefore, the growth retardation by Tween 60 may be responsible for the decreased food intake. In addition to decreased growth rate, exfoliation of the villous tip was observed in rats fed 1% DOC. The growth retardation by DOC may be due to the exfoliation and inhibited activity of digestion-absorption system. GDF and other dietary fibers, such as carboxymethylcellulose konjac mannan and chitosan had no protective effect on DOC toxicity.