A systematic review and meta-analysis «Lindsay KL, Walsh CA, Brennan L ym. Probiotics in ...»1 included two randomised controlled trials (six publications) and one cohort study assessing the effects of probiotics on maternal outcomes. In Finland, 256 women were randomised at their first trimester of pregnancy into three groups: dietary counselling provided by a nutritionist and probiotics (Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12; dietary counselling + probiotics; n= 85), dietary counselling provided by a nutritionist and placebo (dietary counselling + placebo; n=86), and a control group (control+placebo; n=85). Probiotic intervention reduced the incidence of gestational diabetes mellitus (GDM); 13 %, 36% and 34% in the dietary counselling + probiotics, dietary counselling + placebo and control+placebo groups, respectively. The risk of GDM was significantly reduced in the dietary counselling +probiotics group vs control+placebo group (OR 0.27, 95% CI 0.11 to 0.62), but there was no significant difference between dietary counselling +placebo group vs control+placebo group (OR 1.08, 95% CI 0.55 to 2.12). There was no significant difference in mean birth weight (g) among the three groups: 3467 (95% CI 3370 - 3564), 3579 (3469 – 3688) and 3611 (3494 – 3727) in the dietary counselling +probiotics, dietary counselling+placebo and control+placebo groups, respectively. The intervention had also significant effects on maternal blood glucose (base-line adjusted means 4.45, 4.60 and 4.56 mmol/l in dietary counselling +probiotics, dietary counselling +placebo and control+placebo groups respectively, P=0.025) and insulin concentration (adjusted means 7.55, 9.32 and 9.27 respectively, P=0.032). There were no differences in rates of preterm or post-term deliveries, caesarean sections, or Apgar scores. There were no perinatal deaths or serious adverse effects. Neither the other RCT nor the cohort study addressed GDM or glucose metabolism.
Clinical comment: One high-quality double blind RCT. More trials are needed.