For decades, the uterus was considered a sterile environment. Today, we know that the endometrium hosts communities of microorganisms that may influence key processes in reproduction.
However, their role in infertility is still not fully understood.
Understanding how these microorganisms interact with uterine tissue is one of the main challenges in reproductive medicine.
In this context, MicroEndo emerges as an initiative developed within the COCREA program, combining biology, technology, and data analysis to advance this field.
The project will analyze endometrial and fecal samples from women with conditions associated with infertility, such as chronic endometritis, adenomyosis, and Asherman syndrome, collected during the window of implantation, together with samples from fertile women as a control group.
These samples will be studied using techniques such as single-cell transcriptomics and metagenomics, integrating the data to jointly analyze the activity of uterine cells and the composition of the microbiome.
This approach will enable the identification of interaction patterns between both systems, supporting the development of new biomarkers of uterine receptivity and reproductive disorders, and laying the groundwork for precision diagnostics and personalized therapies.
A New Approach to Studying Infertility
Female infertility is often associated with alterations in the endometrium whose underlying causes are not always well understood.
Recent evidence suggests that the endometrial microbiome may play a role in key processes such as uterine receptivity and embryo implantation.
However, understanding these interactions requires integrating multiple layers of biological information. This approach makes it possible to study the endometrium and its microbiome as an integrated system, rather than analyzing them separately, as has traditionally been done.
What Does MicroEndo Bring?
MicroEndo addresses this challenge through an approach based on multi-omics data integration.
This involves the joint study of:
- The genetic activity of endometrial cells
- The composition of the uterine microbiome
- The interactions between both systems
To achieve this, technologies such as single-cell transcriptomics and metagenomics are combined with advanced computational tools capable of integrating and analyzing complex patterns in high-dimensional biological data.
The goal is to move toward a functional, rather than purely descriptive, understanding of the role of the microbiome in fertility.
From Data to Clinical Application
One of the main challenges in reproductive medicine is improving diagnosis and personalizing treatments.
- Functional microbiome-based biomarkers that reflect not only which microorganisms are present, but how they interact with the endometrium and influence its receptive state
- Integrated endometrium–microbiome models to identify alterations associated with infertility, incorporating signals from both the tissue and the microbial community
- New diagnostic strategies based on microbiome–endometrium interactions, offering greater precision than approaches focused solely on the tissue
This approach will help move from a descriptive view of the uterine microbiome toward a functional interpretation with clinical relevance, and may contribute to identifying the causes of some cases of unexplained infertility and improving clinical decision-making in assisted reproduction.
A Collaborative Project
MicroEndo is developed within the CSIC COCREA 2025 program, designed to foster collaboration between research and industry.
The project involves the group led by Dr. Inmaculada Moreno, in collaboration with the spin-off EndoRenew, working on new strategies in endometrial health, and the group led by Dr. Ana Conesa (I2SysBio-CSIC), an international reference in bioinformatics and multi-omics data integration.
This collaboration brings together biomedical research, computational analysis, and clinical application within a shared framework, enabling a more integrated approach to the study of female infertility.