Streptomyces Dominance in Endometrial Microbiomes of In Vitro Fertilization Patients Is Consistent Across Age Groups and Pregnancy Outcomes

Abstract

The endometrial microbiome composition is increasingly recognized as a factor influencing In Vitro Fertilization (IVF) success. While maternal age impacts pregnancy outcomes, its relationship with the endometrial microbial profile remains poorly understood. This study aimed to investigate the diversity and composition of the endometrial microbiome across different maternal age groups (26-50 years) of successful and unsuccessful IVF outcomes by re-analyzing a published 16S rRNA gene dataset from infertile women. QIIME2 and R were used for data processing and data analysis; including alpha diversity, taxonomic composition, core microbiome, and Random Forest modeling. It was found that alpha diversity metrics showed no significant correlation with age or differences between IVF outcome groups. Taxonomic analysis revealed Streptomyces dominance across all age groups and IVF outcomes. Core microbiome analysis confirmed a high similarity between IVF outcomes and across age groups, despite some minor age-specific variations. Random Forest model identified Streptomyces as the most influential ASVs when determining IVF outcome, and due to the lack of compositional differentiation, this likely explained the 55.85% low prediction accuracy of the model. These findings differ significantly from previously identified Lactobacillus-dominant microbiomes, and suggest that Streptomyces dominance may have a role in reproductive challenges. Further investigation is crucial to validate this finding and differentiate it from potential contamination, as well as explore mechanisms by which Streptomyces may impact endometrial function and reproductive health.