Twenty one male Wistar albino rats each weighing approximately 280 g were used in this study. Animals were divided into three groups. The first group (n = 7) consisted of sham controls, in the second (n = 7), rats were administrated 0.1 g/1 ml/galactooligosaccharide by by oral gavage for 4 weeks. In the third group (n = 7), rats were administrated 10(9) CFU/1ml/day Bifidobacterium lactis by oral gavage for 4 weeks. After 4 weeks, rats were sacrified; ileum and proximal colon segments were removed. The spontaneous contractions of ileum and proximal colon were evaluated by using organ bath. It has been detected that both prebiotics and probiotics increased intestinal motility. While probiotics have effects on both ileum and proximal colon, prebiotics seem to be effective in colon. All data are expressed as mean +/- SEM (standard error of mean). Statistical comparisons between groups were performed using general linear models of analysis of variance (ANOVA) followed by the Turkey test.