Efficacy of probiotic supplementation in patients with diabetic nephropathy: A systematic review and meta-analysis

Background Diabetic nephropathy (DN) is one of the diabetes mellitus complications, which develops in approximately one-third of diabetic patients. Probiotics are microorganisms such as Lactobacillus and Bifidobacterium which have some benefits with gastrointestinal disorders and diabetic patients. Aim We aim to assess the efficacy of probiotic supplementation in patients with diabetic nephropathy (DN). Methods We searched PubMed, Scopus, Web of Science, and Cochrane on 20 august 2019 and updated the search on 26 April 2020 using relevant keywords. Studies were screened for eligibility. We extracted the data from the relevant articles and then these data were pooled as mean difference (MD) with a 95% confidence interval (CI), using Review Manager software (ver. 3.5). Results Pooled data from four trials compared probiotics with a placebo showed a significant reduction in insulin (MD = -1.99, 95% CI [-3.99, 0.01]) and Homeostatic Model Assessment for Insulin Resistance (MD = -3.87, 95% CI [-7.51, -0.22]), High-sensitivity C-reactive protein (MD = -1.55, 95% CI [-2.19, -0.92]), malondialdehyde (MD = -0.77, 95% CI [-0.96, -0.58]), sodium (MD = -0.93, 95% CI [-1.87, -0.01]), but the total antioxidant capacity was significantly increased (MD = 62.29, 95% CI [18.34, 106.24]), while no significant effect on other lipid profiles, oxidative stress biomarkers or kidney function parameters like creatinine and glomerular filtration rate. Two trials showed that probiotic soy is better than conventional soy in terms of kidney function and lipid profiles. Conclusion Probiotics supplementation decreases serum insulin and insulin resistance, but it has no beneficial effect regarding kidney function, body-weight, and lipid profiles, with a moderate positive effect regarding some oxidative stress biomarkers. Also, probiotic soy protein may improve kidney function and lipid profiles. Further studies are needed to confirm our findings and to assess the long-term effect.