Randomised control trial indicates micronutrient supplementation may support a more robust maternal microbiome for women with antenatal depression during pregnancy.

Background And Aims: We investigated the effects of high dose dietary micronutrient supplementation or placebo on the human gut microbiome in pregnant women who had moderate symptoms of antenatal depression. There is a significant absence of well-controlled clinical studies that have investigated the dynamic changes of the microbiome during pregnancy and the relationship among diet, microbiome and antenatal depression. This research is among the first to provide an insight into this area of research.

Methods: This 12 - week study followed a standard double blinded randomised placebo-controlled trial (RCT) design with either high dose micronutrients or active placebo. Matching stool microbiome samples and mood data were obtained at baseline and post-treatment, from participants between 12 and 24 weeks gestation. Stool microbiome samples from 33 participants (17 in the placebo and 16 in the treatment group) were assessed using 16s rRNA sequencing. Data preparation and statistical analysis was predominantly performed using the QIIME2 bioinformatic software tools for 16s rRNA analysis.

Results: Microbiome community structure became increasingly heterogenous with decreased diversity during the course of the study, which was represented by significant changes in alpha and beta diversity. This effect appeared to be mitigated by micronutrient administration. There were less substantial changes at the genus level, where Coprococcus decreased in relative abundance in response to micronutrient administration. We also observed that a higher abundance of Coprococcus and higher alpha diversity correlated with higher antenatal depression scores.

Conclusions: Micronutrient treatment appeared to support a more diverse (alpha diversity) and stable (beta diversity) microbiome during pregnancy. This may aid in maintaining a more resilient or adaptable microbial community, which would help protect against decreases or fluctuations that are observed during pregnancy.