Abstract:This study aimed to investigated the effect of Lactobacillus rhamnosus R9639 on intestinal flora and anti-oxidation capacity in mice.Forty-four BALB/c mice were randomly divided into control，low，medium，and high dose groups.They were gavaged with equal doses of saline and different doses of Lactobacillus rhamnosus R9639 preparations for 30 days.On days 0 and 30，fecal samples of the mice were collected for viable bacteria counting and short-chain fatty acid determination.The T-SOD，MDA，GSH，and GSH-Px levels in the small intestine and liver tissues，and those of IL-2，IL-6，IL-1β，and TNF-α in the serum，were measured.Compared to the control group，there was no significant difference in body weight，food intake，organ coefficients，or weight and length of the small intestines.However，the levels of inflammatory factors IL-2，IL-6，IL-1β，and TNF-α were reduced compared to those in the control group.Compared to the control group，the T-SOD，GSH，and GSH-Px levels in the high dose group of small intestine tissues were highly significantly increased （p＜0.01），and MDA levels were highly significantly decreased （p＜0.01）in the medium and high dose groups.In the liver tissues，the T-SOD，GSH，and GSH-Px levels were highly significantly increased（p＜0.01）in the medium and high dose groups，and MDA levels were significantly decreased （p＜0.05）in the high dose group.The numbers of Lactobacillus and Bifidobacterium were significantly different （p＜0.01）in the medium and high dose groups compared to those in the control group and itself pre-and post-gavage.Compared to the control group，acetic acid，propionic acid，and butyric acid in the medium and high dose groups were highly significantly different（p＜0.01）.Collectively，Lactobacillus rhamnosus R9639 preparation has a positive effect on regulating the intestinal flora and improving the anti-oxidation capacity of mice.