Association between gut microbiota and postpartum depression: A bidirectional Mendelian randomization study

Backgrounds: Empirical investigations have shown an association between gut microbiota and postpartum depression (PPD); nevertheless, the precise cause-and-effect relationship between these two variables remains ambiguous. This research aimed to examine the possible reciprocal causal relationship between the gut micro- biota and PPD. Methods: In this work, we used Mendelian randomization (MR) to analyze the relationship between the gut microbiota (n n = 18,340) and PPD (n n = 67,205). We obtained the relevant SNPs from publicly accessible genomewide association studies (GWAS). The SNP estimations were combined by the inverse-variance weighted (IVW) method, including sensitivity analyses such as weighted median, MR Egger, and MR Pleiotropy Residual Sum and Outlier (PRESSO). Results: We have identified strong correlations between six bacterial characteristics and the likelihood of developing PPD. Our research revealed that the genus Ruminococcaceae UCG010, the family Veillonellaceae, and the class Clostridia had a beneficial effect on preventing PPD. The class Alphaproteobacteria, genus Slackia, and order NB1n were found to have a significant negative impact on PPD. The sensitivity studies conducted on these bacterial features consistently confirmed these finding. Limitations: It is crucial to acknowledge that our study was conducted just within a European society, which may restrict its applicability to other groups. Conclusions: The findings from our MR investigation indicate a potential causal relationship between certain kinds of gut bacteria and PPD. Additional investigation is required to elucidate the influence of gut microbiota on the advancement of PPD.