Effects of probiotic supplements on insulin resistance in gestational diabetes mellitus: A double‐blind randomized controlled trial

AIMS/INTRODUCTION: To evaluate the effect of probiotic supplements on insulin resistance in pregnant women with diet‐controlled gestational diabetes mellitus. MATERIALS AND METHODS: A randomized, double‐blind, placebo‐controlled trial was carried out between June 2016 and February 2017. Pregnant women with diet‐controlled gestational diabetes mellitus were enrolled in the study at 24–28 weeks‐of‐gestation and randomized to receive either probiotic supplements containing Bifidobacterium and Lactobacillus or a placebo daily for four consecutive weeks. Primary outcomes were mean differences in insulin resistance (homeostatic model assessment for insulin resistance), fasting insulin and fasting plasma glucose between the two groups. Secondary outcomes were changes in maternal weight after the intervention. RESULTS: Data from 28 patients in the probiotic group and 29 in the placebo group were analyzed. The changes in metabolic parameters after randomization showed significant improvement in glucose metabolism in the probiotic group compared with the placebo group, including fasting plasma glucose (0.68 ± 5.88 vs 4.620 ± 7.78 mg/dL, mean difference −3.94 mg/dL, 95% confidence interval −7.62, −0.27, P = 0.034), fasting plasma insulin (1.11 ± 1.71 vs 3.77 ± 1.70 mIU/L, mean difference −2.67 mIU/L, 95% confidence interval −3.57, −1.76, P = 0.001) and homeostatic model assessment for insulin resistance (0.25 ± 0.37 vs 0.89 ± 0.46, mean difference −0.63, 95% confidence interval −0.86, −0.41, P = 0.001). Weight gain during randomization was similar between the two groups. CONCLUSIONS: Four weeks of probiotic supplements in women with diet‐controlled gestational diabetes in the late second and early third trimester lowered fasting glucose and increased insulin sensitivity. Probiotic supplements may be considered as an adjunct treatment for glycemic control in these patients.