ABSTRACT
Lactobacillus plantarum has been shown to improve glucose and lipid metabolism in mouse models of type 2 diabetes mellitus (T2DM). However, it remains unclear whether such benefits extend to humans. A systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to clarify the effect of L. plantarum supplementation on glucose and lipid metabolism in T2DM and prediabetes. The PubMed, Cochrane, and Web of Science databases were searched. A random-effects model was used to estimate the pooled mean difference with 95% CI (confidence interval). L. plantarum supplementation reduced the levels of fasting plasma glucose (-0.41, 95%CI -0.63, -0.19 mg/dL; n = 5) and hemoglobin A1c (-0.2, 95%CI: -0.3, 0%; n = 4). A non-statistically significant tendency towards improvements in the Homeostatic Model Assessment for Insulin Resistance (MD: -0.74, 95%CI: -1.72, 0.25; n = 3), low-density lipoprotein cholesterol (-6.87; 95%CI: -15.03, 1.29 mg/dL; n = 3), high-density lipoprotein cholesterol (MD: 1.34; 95%CI: -0.78, 3.46 mg/dL; n = 3), triglyceride (MD: -3.90; 95%CI: -11.05, 3.24 mg/dL; n = 3), and total cholesterol (MD: -4.88; 95%CI: -11.84, 2.07 mg/dL; n = 3) was observed with the supplementation. In summary, while the evidence from the currently available RCTs provides a crude indication that L. plantarum supplementation might improve glucose and lipid metabolism in patients with T2DM and prediabetes, the benefits of the supplementation are likely subtle, and its clinical significance requires further investigation.