Probiotic Properties in Vitro and in Vivo of Antioxidative Lactic Acid Bacteria from Yak Yogurt in Tibetan Plateau

Objective: To screen for lactic acid bacteria with excellent probiotic and antioxidant properties and to study their anti-aging effect on D-galactose-induced aging mice. Methods: Three strains of lactic acid bacteria with high antioxidant activity were isolated from yak yogurt in the Tibetan Plateau, and their probiotic properties in vitro were evaluated in terms of tolerance to simulated gastrointestinal fluid and bile salts and hydrophobic ability. The best strain was further selected and fed to the aging model mice. The probiotic properties in vivo were evaluated by organ indexes, glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) activities, total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content in brain tissue and serum of rats from each treatment group. Results: Lactobacillus plantarum XM5 had strong resistance to simulated gastrointestinal fluid and bile salt, and also had high hydrophobic ability. Intake of L. plantarum XM5 could effectively alleviate the oxidative damage in rat brain induced by D-galactose, significantly increase GSH-Px activity in liver, GSH-Px and T-SOD activities and T-AOC in serum and significantly reduce MDA content in liver, brain tissue and serum (P © 2017, China Food Publishing Company. All right reserved.