Gestational diabetes mellitus (GDM) is one of the most frequent metabolic complications of pregnancy and its prevalence is up to 12% in developed countries. Nowadays, several studies are investigating new therapies for glucose control that may complement diet, exercise, and pharmacological therapies. Among them, probiotics potentially represent a novel way to improve maternal metabolic and pregnancy outcomes. However, there are scarce randomized controlled trials (RCTs) to date that have directly investigated the glycemic effects of probiotics among women with GDM. In addition, the studies that have been completed have reported a mix of positive and null outcomes. Noticeably, studies that investigate the effect of probiotics when taken after diagnosis of GDM are scarce.

A recent double-blind placebo-controlled RCT, which was led by Dr. Mehran Mesgari Abbasi from the Drug Applied Research Centre at Tabriz University of Medical Sciencies in Iran, found that a probiotic capsule taken once daily for 8 weeks may affect glucose metabolism and weight gain among pregnant women with GDM.


Briefly, 64 pregnant women with GDM were randomized to a daily probiotic (Lactobacillus acidophilus LA-5, Bifidobacterium BB-12, Streptococcus thermophilus STY-31 and Lactobacillus delbrueckii bulgaricus LBY-27 at a target dose of > 4 x 109 colony-forming units) or placebo capsule along with dietary advice for 8 consecutive weeks. Fasting blood samples were collected before and after the intervention. Primary outcomes were the women’s trend of weight gain and glucose metabolism indices, which included fasting blood glucose, fasting serum insulin, homeostasis model assessment insulin resistance (HOMA-IR) index, and quantitative insulin sensitivity check (QUICKI) index.


In the last 2 weeks of the study, the weight gain in the probiotic group was significantly lower than in the placebo group. Regarding glucose metabolism indices, fasting blood glucose and HOMA-IR index in the probiotic group significantly decreased over the study period. However, the post-intervention insulin sensitivity index in the probiotic group was not significantly different from placebo.


In conclusion, probiotic supplementation seems to have a beneficial effect on weight gain and glucose metabolism among pregnant women with GDM. However, whether the outcomes in maternal metabolic parameters detected in this study can translate to clinically meaningful outcomes deserves further randomized trials. With more study, researchers may fully elucidate the potential effect of probiotics among this important obstetric group at risk of future metabolic syndrome.





Dolatkhah N, Hajifaraji M, Abbasalizadeh F, Aghamohammadzadeh N, Mehrabi Y, Abbasi MM. Is there a value for probiotic supplements in gestational diabetes mellitus? A randomized clinical trial. Journal of Health, Population and Nutrition. 2015;33:25.