Relevant related studies:
Evidence that the endometrial microbiota has an effect on implantation success or failure. Moreno, Inmaculada et al. American Journal of Obstetrics & Gynecology, Volume 215, Issue 6, 684 – 703.
Human Microbiome Project Consortium. Structure, function and diversity of the healthy human microbiome. Nature 2012; 486:207–14.