09/03/2026
Did you know your uterus has its own microbiome?
For years, we focused on the va**nal microbiome, however emerging research is revealing that the endometrial microbiome (the bacteria living inside your uterine lining) plays a critical and distinct role in reproductive health.
Here's what the science is showing us π
What lives in your endometrium matters. Lactobacillus-dominant endometrial flora is associated with successful embryo implantation, healthy pregnancy maintenance, and reduced risk of miscarriage. Studies in IVF populations show that women with low Lactobacillus in the endometrium have significantly poorer reproductive outcomes. (Moreno et al., 2016, AJOG)
This is super important for women undergoing IVF. Research shows women with higher Lactobacillus levels at embryo transfer have significantly better IVF outcomes. (Moreno et al., 2016; Kyono et al., 2019)
Your va**nal and endometrial flora are NOT the same, however they influence each other.
Research has found that as you move up the ge***al tract, microbial populations change β and in up to 20% of women, the endometrial microbiome differs substantially from the va**nal microbiome. You cannot assume va**nal health = uterine health. (Chen et al., 2021, Frontiers in Cellular and Infection Microbiology). Interestingly, The endometrium is anatomically isolated compared to the va**na, and its microbial ecosystem is shaped by hormonal fluctuations across the menstrual cycle, IVF medications, and immune responses.
Dysbiosis in the endometrium is linked to:
Recurrent implantation failure (RIF) ~ with elevated Streptococcus, Staphylococcus, Neisseria, and Klebsiella found in 40β60% of affected women (Torres et al., 2024)
Recurrent pregnancy loss (RPL) ~ with Gardnerella va**nalis, Bacteroides, Atopobium, and Prevotella consistently identified (Torres et al., 2024; Moreno et al., 2022)
Chronic endometritis ~ driven by pathogens including Enterococcus, E. coli, Streptococcus, Staphylococcus, Mycoplasma, and Ureaplasma (Liu et al., 2019)
Endometriosis ~ presents with reduced Lactobacillus and elevated Streptococcaceae,
Continued ππ»