Early pregnancy probiotic supplementation with Lactobacillus rhamnosus HN001 may reduce the prevalence of gestational diabetes mellitus: a randomised controlled trial

The study aims to assess whether supplementation with the probiotic Lactobacillus rhamnosus HN001 (HN001) can reduce the prevalence of gestational diabetes mellitus (GDM). A double-blind, randomised, placebo-controlled parallel trial was conducted in New Zealand (NZ) (Wellington and Auckland). Pregnant women with a personal or partner history of atopic disease were randomised at 14-16 weeks' gestation to receive HN001 (6 x 10(9) colony-forming units) (n 212) or placebo (n 211) daily. GDM at 24-30 weeks was assessed using the definition of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) (fasting plasma glucose >= 5.1 mmol/l, or 1 h post 75 g glucose level at >= 10 mmol/l or at 2 h >= 8.5 mmol/l) and NZ definition (fasting plasma glucose >= 5.5 mmol/l or 2 h post 75 g glucose at >= 9 mmol/l). All analyses were intention-to-treat. A total of 184 (87 %) women took HN001 and 189 (90 %) women took placebo. There was a trend towards lower relative rates (RR) of GDM (IADPSG definition) in the HN001 group, 0.59 (95% CI 0.32, 1.08) (P = 0.08). HN001 was associated with lower rates of GDM in women aged >= 35 years (RR 0.31; 95% CI 0.12, 0.81, P= 0.009) and women with a history of GDM (RR 0.00; 95% CI 0.00, 0.66, P = 0.004). These rates did not differ significantly from those of women without these characteristics. Using the NZ definition, GDM prevalence was significantly lower in the HN001 group, 2.1% (95% CI 0.6, 5.2), v. 6.5% (95% CI 3.5, 10.9) in the placebo group (P = 0.03). HN001 supplementation from 14 to 16 weeks' gestation may reduce GDM prevalence, particularly among older women and those with previous GDM.