Abstract: Purpose: The aim is to investigate the effect of oatβ-glucan with different molecular weights on intestinal flora in mice. Methods: 90 mice were divided into five groups (control and 1～4 groups).The group 1 and 2 were administered oatβ- glucan (MW2.6×106) at dose of 0.25g/kg·d and 0.5g/kg·d daily for 28d as well as group 3 and 4 administered oatβ-glucan (MW 3.7×105).The control group was received the equal volume of normal saline. We analyzed the intestinal flora at 14d, 28d and 35d (after terminating oatβ-glucan for 1 week) and compared body weights ,pH of the intestinal contents in each group. Results The number of Bifidobacterium and Lactobacillus increased, Enterobacillus decreased in experimental groups compared with the control in the intestine and faeces. The same dose groups had no significant differences(p>0.05), but the higher dose groups shaved significant differences compared with the lower dose groups in different molecular weights(p<0.05).The body weight and pH in the intestinal contents were significantly reduced in group 2 and 4(p<0.05). This study demonstrated that oat β-glucan have had the function of regulating the intestinal flora with impact on gut.

Key words: oat β-glucan, intestinal flora