Effectiveness of probiotics in type 2 diabetes: a meta-analysis

INTRODUCTION An increasing number of studies suggest that the use of probiotics may have a beneficial effect in patients with type 2 diabetes. OBJECTIVES The aim of the study was to assess the ability of probiotics to modify selected cardiometabolic risk factors in subjects with type 2 diabetes. METHODS PubMed, Embase, Cochrane Library, and Scopus databases were thoroughly reviewed up to January 2015 to search for randomized controlled trials (RCTs) that examined the effect of probiotics on selected modifiable cardiometabolic parameters in patients with type 2 diabetes. The following endpoints were considered: fasting plasma glucose (FPG), insulin concentration, insulin resistance, hemoglobin A(1c) (HbA(1c)), as well as the levels of total cholesterol, triglycerides, low-density and high-density lipoprotein cholesterols, and C-reactive protein (CRP). A total of 571 RCTs were initially identified, of which 8 trials with 438 individuals were selected for meta-analysis. The effects of probiotics were calculated for each parameter. RESULTS The meta-analysis showed a significant effect of probiotics on reducing HbA(1c) levels (standardized mean difference [SMD], -0.81; confidence interval [CI], -1.33 to -0.29, P = 0.0023; I-2 = 68.44%; P = 0.0421 for heterogeneity) and HOMA-IR (SMD, -2.10; CI -3.00 to -1.20, P < 0.001; I-2 = 82.91%; P = 0.0029 for heterogeneity). Supplementation with probiotics did not have a significant effect on FPG, insulin, and CRP levels as well as the lipid profile. CONCLUSIONS Our meta-analysis suggests that probiotic supplementation might improve, at least to some extent, metabolic control in subjects with type 2 diabetes. However, larger well-designed, long-term RCTs are needed to confirm any potentially beneficial relationship between the use of probiotics and modifiable cardiometabolic risk factors in patients with type 2 diabetes.