The Impact of Probiotic Soy Milk Consumption on Oxidative Stress Among Type 2 Diabetic Kidney Disease Patients: A Randomized Controlled Clinical Trial

Abstract

Diabetic kidney disease (DKD) is one the most important complications of diabetes leading to end-stage renal disease. This study aimed to determine the effects of probiotic soy milk consumption on oxidative stress biomarkers in type 2 DKD patients. Forty-eight patients were randomly assigned to consume a diet containing 200mL/day probiotic soy milk in the intervention group or soy milk in the control condition. As determinants of oxidative stress, malondialdehyde, 8-iso-prostaglandin F2α, oxidized glutathione, total antioxidant capacity, reduced glutathione (GSH), glutathione peroxidase, and glutathione reductase were measured after 8weeks of intervention according to the standard protocol. Between groups analysis showed that DKD patients in the probiotic soy milk group had a higher mean value of GSH compared with those in the soy milk group. In the final adjusted model, this difference remained significant. Consistently, oxidized glutathione concentration was significantly reduced among patients in the probiotic soy milk group. Also, for activity levels of antioxidant enzymes including glutathione peroxidase and glutathione reductase, significant increased levels were observed between 2 intervention groups in the final adjusted model. However, no significant reduction of the serum 8-iso-prostaglandin F2α or malondialdehyde and no induction of TAC concentrations within and between the 2 groups in the crude and adjusted models were detected. Overall, the results demonstrate that probiotic soy milk consumption could improve some oxidative stress factors among DKD patients. Further longitudinal studies with consideration of individual variation should be conducted.