Improvement of glucose metabolism in pregnant women through probiotic supplementation depends on gestational diabetes status: meta-analysis

Randomized controlled trials; pregnant women aged 18–45; included women with and without gestational diabetes mellitus (GDM); 1119 participants across 15 trials; populations from Asian and Caucasian groups.

Probiotic capsules daily (various Lactobacillus and Bifidobacterium strains) for 4–12 weeks; some trials used probiotic-enriched yogurt; synbiotic capsules daily; dosages ranged from 10^6 to >10^10 CFU per capsule; prebiotics used as part of synbiotics (isomalt, sorbitol, inulin, fructo-oligosaccharides).

Supplementation lowers fasting glucose, fasting insulin, and HOMA-IR in pregnant women with GDM; glucose reduction significant only with probiotics (not synbiotics); insulin and HOMA-IR reductions occur with both probiotic and synbiotic formulations; overall, probiotic supplementation may improve glucose metabolism in pregnant women with GDM; more large randomized trials are needed to confirm effects and optimize regimen and to determine effects in women without GDM.

Variability in probiotic strains, doses, and duration across studies; small sample sizes (roughly 30–40 per trial); incomplete reporting of some outcomes (fasting glucose reported in most but not all studies; insulin/HOMA-IR in others); heterogeneity among trials; potential publication bias; limited control for diet, physical activity, and baseline microbiota; synbiotic formulations complicate direct comparison with probiotics.