Effect of probiotic supplementation on glycemic control in patients with type 2 diabetes: A randomized controlled trial.

Background: Type 2 diabetes presents significant public health challenges. The gut microbiome has emerged as a potential factor influencing glucose metabolism.

Methods: We performed a randomized, double-blind, single-center trial involving patients with type 2 diabetes and glycated hemoglobin (HbA1c) concentration of 7 % or greater. Patients were randomly assigned to receive 100 billion colony-forming units (CFUs) of probiotic supplementation daily or placebo. The primary efficacy endpoint was the change in HbA1c from baseline to 12 weeks, and secondary endpoints included lipid and inflammatory markers.

Results: A total of 130 patients were included. HbA1c was 7.63 ± 0.54 % at baseline and 7.63 ± 0.63 % at 12 weeks in the probiotic group and 7.71 ± 0.74 % and 7.81 ± 0.84 % in the placebo group (p = 0.29 between treatment groups). There were also no significant differences between treatment groups in plasma glucose (p = 0.60) and insulin (p = 0.41), as well as in LDL-cholesterol (p = 0.90) and triglycerides (p = 0.32). The adjusted geometric mean percent change (95 % confidence interval) in high-sensitivity C-reactive protein was 1.59 % (-15.71, 22.44) in the probiotic group and -1.37 % (-18.04, 18.70) in the placebo group (p = 0.82). Gastrointestinal adverse events occurred in 38.5 % and 46.2 % of patients in the probiotic group and placebo group respectively (p = 0.48).

Conclusions: Probiotic supplementation for 12 weeks did not improve glycemic control, lipid or inflammatory markers in patients with type 2 diabetes. Further research is needed to determine the potential benefits and underlying mechanisms of probiotics in subsets of patients.

Clinicaltrials: gov Identifier no. NCT03239366.