Introduction: A National Effort to Map the Hidden Health Axis
A pioneering national study in Portugal is underway to explore the so called invisible axis between intestinal microbiota and hormonal changes during perimenopause and menopause. The goal is to prevent chronic symptoms and improve the health trajectory of women through midlife and beyond.
Led by Ana Santos Almeida, principal investigator at the Gulbenkian Institute of Molecular Medicine and head of the Translational Microbiome Lab in Health and Disease, the project seeks to move beyond traditional views of menopause by examining the gut as a key player in hormonal health.
“There is an axis between hormones and gut bacteria that remains largely invisible today,” Almeida explains, outlining a research program that aims to unravel how microbial communities influence and reflect hormonal shifts.
The invisible axis between hormones and the gut microbiota
Menopausal symptoms, which affect a large share of women, span physical, emotional and sexual well being. The study posits that the gut microbiota may modulate the experience of menopause by interacting with declining estrogen levels. Estrogen plays a central role during this life stage, and its reduced production can elevate the risk of chronic conditions such as depression and certain cancers, including breast cancer. The team is investigating how intestinal bacteria metabolize estrogen, potentially recycling or excreting it, thereby influencing the hormonal landscape inside the body.
“This is a very new area of research,” says Almeida, underscoring the potential for microbiota to become a lever in managing menopausal health. The project also recognizes that microbiota composition can respond to diet and lifestyle, offering a possible pathway for nonpharmacological interventions.
How the study will be conducted
The researchers are collecting data from women aged 40 to 64, the window of perimenopause and menopause, through the GIMM Biobank as part of the Semana da Mama initiative. The goal is to assemble a dataset from about 300 participants, including blood and fecal samples alongside information on dietary habits and lifestyle.
As Almeida notes, stool samples are far from unappealing in conception. A pea sized amount, processed with modern sequencing technologies, can reveal thousands of bacterial species and their functions. Blood samples will provide hormonal profiles and markers of inflammation linked to aging and menopause, enabling a comprehensive view of the hormonal and microbial interplay.
From data to prevention: turning findings into risk models
With the collected data, the team plans to apply machine learning to build models that integrate hormonal data, microbiota composition and nutrition. The aim is to identify whether specific microbial patterns can serve as biomarkers of menopausal symptoms or as predictors of disease risk. These models could eventually guide personalized strategies to reduce symptom burden and prevent long term complications as women age.
“Unlike our genes, the microbiota is highly modifiable by what we eat and how we live,” Almeida emphasizes. The long term objective is to develop actionable insights that help identify who is at higher risk for certain conditions and to tailor microbiota directed interventions to reduce that risk.
<h2Collaborators, funding and the road ahead
The project currently enjoys support from the Biocodex Foundation Portugal. The multidisciplinary team also includes Ana Teresa Freitas from INESC ID and Catarina Sousa Guerreiro from the Faculty of Medicine of Lisbon, with the hope of expanding participation to more women and following them over time to improve the precision of risk models.
By integrating hormone data, microbiota profiles and dietary information, the study aspires to transform menopausal care from a reactive to a proactive model, emphasizing intestinal health as a central pillar of lifelong womens health in Portugal and beyond.
