Causal relationship between immune cells, metabolites and polycystic ovary syndrome identified by Mendelian randomization and mediation analyses

%B cells and PCOS. Finally, reverse MR studies did not identify any reverse causation between the 22 immune cell phenotypes and PCOS. This study elucidates the causal links between immune cells and PCOS, highlighting the potential roles of four blood metabolites in mediating the interaction between immune cells and PCOS, thus providing new targets for research and therapeutic interventions.