(153) Oral probiotic versus placebo and the maternal metabolome during pregnancy: A randomized controlled trial

Objective:
The original aim of this study was to investigate whether an oral probiotic with a mixture of Lactobacillus and Bifidobacterium species could change the vaginal microbiome during pregnancy, and the results showed overall no change. Studies suggest a complex interplay between the microbiome and metabolome during pregnancy, which can have an impact on perinatal outcomes. Therefore, a secondary aim was to examine the influence of the oral probiotic on the maternal metabolome.

Study Design:
This was a pilot randomized double-blinded placebo-controlled trial at a university hospital. Healthy singleton pregnancies were enrolled between 6w0d and 13w6d and randomized to an oral probiotic or placebo. Samples from the vagina, urine, and anus were obtained prior to randomization and 4-6 weeks after intervention. Samples were extracted using ideal conditions for small molecule reverse phase positive mode untargeted metabolomics and run using a high-performance mass spectrometer coupled to a liquid chromatography system. Data was analyzed using GNPS and QIIME2.

Results:
48 patients were enrolled, and 43 completed the study, with 22 randomized to the placebo, and 21 to the probiotic. 3 patients in the probiotic group developed vaginal infections requiring treatment during the study period and were excluded from the analysis (Figure 1). The groups were similar in baseline characteristics and metabolomic profiles for all sample sites. Post-intervention, the groups remained similar. Comparing pre versus post intervention with Bray Curtis distance metric PCoA, there was no significant difference in the metabolome for the placebo group (Figure 2; A, D, G) or the probiotic group (B, E, H). Comparing the placebo versus probiotic groups with paired longitudinal distance boxplots, there was no significant shift in the metabolome for participants (C, F, I).

Conclusion:
The overall vaginal, urine, and anal metabolomes did not change significantly after the introduction of an oral probiotic into the maternal diet, and the metabolomes appeared relatively stable over the course of 4-6 weeks during the first half of pregnancy.