The effect of oral probiotics on glycemic control of women with gestational diabetes mellitus—a multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND: Gestational diabetes mellitus should be treated adequately to avoid maternal hyperglycemia-related complications. Previously, probiotic supplements were suggested to improve fasting blood glucose in women with gestational diabetes mellitus. However, a major limitation of previous studies was that preprandial and especially postprandial glucose values, which are important predictors of pregnancy outcomes, were not studied. OBJECTIVE: This study aimed to examine the effect of a mixture of probiotic strains on maternal glycemic parameters, particularly preprandial and postprandial glucose values and pregnancy outcomes among women with gestational diabetes mellitus. STUDY DESIGN: A multicenter prospective randomized, double-blind, placebo-controlled trial was conducted. Women newly diagnosed with gestational diabetes mellitus were randomly allocated into a research group, receiving 2 capsules of oral probiotic formula containing Bifidobacterium bifidum, B lactis, Lactobacillus acidophilus, L paracasei, L rhamnosus, and Streptococcus thermophilus (>6 × 10⁹/capsule), and a control group, receiving a placebo (2 capsules/day) until delivery. Glycemic control was evaluated by daily glucose charts. After 2 weeks, pharmacotherapy was started in case of poor glycemic control. The primary outcomes were the rate of women requiring medications for glycemic control and mean daily glucose charts after 2 weeks of treatment with the study products. RESULTS: Forty-one and 44 women were analyzed in the treatment and placebo cohorts, respectively. Mean daily glucose during the first 2 weeks in the probiotics and placebo groups was 99.7±7.9 and 98.0±9.3 mg/dL, respectively (P=.35). The rate of women needing pharmacotherapy because of poor glycemic control after 2 weeks of treatment in the probiotics and placebo groups was 24 (59%) and 18 (41%), respectively (P=.10). Mean preprandial and postprandial glucose levels throughout the study period were similar between the groups (P>.05). There were no differences in maternal and neonatal outcomes, including birthweight and adverse effect profile between the groups. CONCLUSION: The oral probiotic product tested in this study did not affect glycemic control of women with gestational diabetes mellitus.