To our knowledge, data on the effects of probiotic supplementation on glycaemic control and lipid concentrations in patients with gestational diabetes mellitus (GDM) are scarce.

The aim of the present study was to determine the effects of probiotic supplementation on glycaemic control and lipid profiles in GDM patients.

Sixty pregnant women with GDM, primigravida and aged 18–40years, were divided into two groups to receive either probiotic capsules (n=30) or a matching placebo (n=30) in this randomized double-blind, placebo-controlled trial. The patients in the probiotic group took a daily capsule that contained three viable freeze-dried strains: Lactobacillus acidophilus (2×10⁹CFU/g), L. casei (2×10⁹CFU/g) and Bifidobacterium bifidum (2×10⁹CFU/g) for 6weeks. The placebo group took capsules filled with cellulose for the same time period. Fasting blood samples were taken at the beginning and end of the study to quantify the relevant markers.

After 6weeks of intervention, probiotic supplementation vs a placebo resulted in significant decreases in fasting plasma glucose (−9.2±9.2mg/dL vs +1.1±12.2mg/dL, P<0.001), serum insulin levels (−0.8±3.1μIU/mL vs +4.5±10.6μIU/mL, P=0.01), homoeostasis model assessment (HOMA) for insulin resistance (−0.4±0.9 vs +1.1±2.5, P=0.003) and HOMA for β-cell function (+1.1±9.8 vs +18.0±42.5, P=0.03), and a significant increase in the quantitative insulin sensitivity check index (+0.007±0.01 vs −0.01±0.02, P=0.007). In addition, significant decreases in serum triglycerides (−1.6±59.4mg/dL vs +27.1±37.9mg/dL, P=0.03) and VLDL cholesterol concentrations (−0.3±11.9mg/dL vs +5.4±7.6mg/dL, P=0.03) were seen following supplementation with the probiotics compared with the placebo. However, no significant changes in other lipid profiles were seen with the intervention.

Overall, the results of our study have demonstrated that taking probiotic supplements for 6weeks in patients with GDM had beneficial effects on glycaemic control, triglycerides and VLDL cholesterol concentrations, although there was no effect on other lipid profiles.