BACKGROUND AND AIMS: Modulation of the gut microbiome composition with probiotics may have beneficial metabolic effects in pregnant women with obesity. The aim was to investigate the effect of probiotic supplementation during pregnancy on metabolic and inflammatory markers and the body composition of the offspring.

METHODS AND RESULTS: A randomized double-blind trial in 50 pregnant women (pre-pregnancy BMI ≥30 and < 35 kg/m 2) comparing multi-strain probiotics (Vivomixx®; 450 billion CFU/d) versus placebo from 14 to 20 weeks of gestation until delivery was carried out. Participants were followed with two predelivery visits at gestational week 27-30 and 36-37 and with one postdelivery visit. All visits included fasting blood samples (C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin, C-peptide, glucose, glucagon, and glucagon-like peptide-1 (GLP-1)). At delivery, umbilical cord blood samples were collected (GLP-1 and glucagon). At the postdelivery visit, a dual-energy X-ray absorptiometry (DXA) scan of the newborn was performed. Forty-nine of 50 participants completed the study until delivery, and 36 mother-offspring dyads underwent postdelivery examinations including a DXA scan. There were no significant differences in changes in measured biomarkers between the probiotic versus the placebo group. No differences were found in newborn body composition or GLP-1 and glucagon. GLP-1 measured in umbilical blood samples was positively correlated to fat percent in offspring from the probiotic group.

CONCLUSION: In this study of pregnant women with obesity and their newborns, there was no effect of probiotic supplementation in mothers or babies on metabolic or inflammatory biomarkers or on body composition of offspring. This study was registered at clinicaltrials.gov as NCT02508844.