Overview: A new frontier in women’s health
In Portugal, researchers are tackling a growing concern: almost 60% of women report that menopausal symptoms negatively affect daily life, from family dynamics to sexual wellbeing. A national research project aims to explore what researchers call the “invisible axis of women’s health” by examining the gut microbiota during perimenopause and menopause, with the goal of developing strategies to support women’s health throughout life.
The invisible axis: hormones and the gut microbiota
The study centers on the interaction between hormones and intestinal bacteria. Ana Santos Almeida, a leading investigator at the Gulbenkian Institute of Molecular Medicine (GIMM) and head of the Translational Microbiome Lab, explains that the gut microbiota may modulate estrogen levels through metabolism and recycling, thereby influencing the hormonal trajectory of menopause.
The decline in estrogen during menopause increases the risk of chronic diseases such as depression and certain cancers, underscoring the potential importance of the microbial ecosystem in mitigating these risks.
As Almeida notes, “there is an axis between what is hormonal and the gut bacteria, which for now is the ‘invisible axis of women’s health’.” The goal is to lift the veil on this relationship and understand how intestinal bacteria could impact symptom burden and long-term health.
Study design: gathering data from 300 women aged 40–64
The project is currently collecting samples through the GIMM Biobank as part of the “Breast Cancer Awareness Week” initiative. Researchers will obtain blood and stool samples, along with detailed information on dietary habits, from 300 women in the perimenopausal and menopausal windows. They emphasize that stool samples, despite a common aversion, can reveal a wealth of information: a pea-sized amount can enable sequencing of billions of gut bacteria and help identify the activity of various microbial players in estrogen metabolism and inflammation.
Blood samples will be used to measure hormones and inflammatory markers related to aging and menopause. The combined data set — hormonal profiles, microbiota composition, and nutrition information — will form the basis for advanced analyses.
From data to risk models: AI and the microbiome
The team plans to apply machine learning to integrate hormonal data, microbial communities, and diet to build risk and association models. These models could reveal whether certain microbiota patterns act as biomarkers for menopausal symptoms or elevated disease risk. “Unlike our genes, the microbiota is highly modifiable by factors such as diet,” Almeida remarks, highlighting the potential for intervention through lifestyle changes and personalized nutrition.
In the long term, the researchers hope to identify interventions that can modulate the gut microbiota to prevent or lessen chronic conditions associated with menopause, effectively personalizing care across a woman’s life course.
Why this matters for women’s health
Understanding the gut–hormone axis could transform how clinicians approach menopause. By recognizing the microbiota’s role in estrogen metabolism and systemic inflammation, physicians might better predict symptom trajectories and disease risk, enabling earlier and more targeted interventions.
Team, funding, and future directions
The project brings together a multidisciplinary team, including Ana Santos Almeida (GIMM), Ana Teresa Freitas (INESC-ID), and Catarina Sousa Guerreiro (Faculdade de Medicina de Lisboa). The work is currently funded by the Biocodex Foundation Portugal, with ambitions to expand the cohort and extend follow-up so models of risk become more precise and clinically useful. As the team puts it, the ultimate aim is to empower women with knowledge and tools to protect health during menopause and beyond.
With additional support, the researchers hope to broaden participation and refine predictive models, aligning with broader efforts to personalize women’s health care. If successful, this national study could pave the way for microbiota-informed strategies that complement hormonal therapy and lifestyle interventions, reducing the burden of menopause-related symptoms and chronic disease.
