Effect of Daily Consumption of Probiotic Yogurt on Oxidative Stress in Pregnant Women: A Randomized Controlled Clinical Trial (Publication with Expression of Concern. See JAN, 2023)

Background: Due to the enhanced oxygen requirement of the mitochondria-rich placenta primarily during the third trimester, pregnancy is associated with elevated levels of oxidative stress. This study was designed to determine the effects of daily consumption of probiotic yogurt on oxidative stress among Iranian pregnant women. Methods: This randomized single-blind controlled clinical trial was performed among 70 pregnant women, singleton primigravida, aged 18-30 in their third trimester. Subjects were randomly assigned to two groups to consume 200 g/day of either conventional yogurt (n = 33) or probiotic yogurt (n = 37) for 9 weeks. Fasting blood samples were taken at baseline and after a 9-week intervention to measure oxidative stress parameters. Results: Consumption of probiotic yogurt resulted in increased erythrocyte glutathione reductase (GR) levels as compared to the conventional yogurt (p = 0.01). Despite the significant effect of probiotic yogurt consumption on plasma glutathione (67.9 mu mol/l, p = 0.01), erythrocyte glutathione peroxidase (163 mmol/min/ml, p = 0.04) and serum 8-oxo-7,8-dihydroguanine levels (-74.3 ng/ml, p = 0.04), no significant differences were found between the two yogurts in terms of their effects on the mentioned parameters. Conclusion: Consumption of probiotic yogurt among pregnant women resulted in increased levels of erythrocyte GR as compared to the conventional yogurt, but could not affect other indices of oxidative stress. Copyright (C) 2012 S. Karger AG, Basel