A study conducted by Catarina R. Marques, a researcher at CESAM/DBIO, has been published in Frontiers in Microbiology and provides the first characterisation of changes in the gut microbiota across the colorectal adenoma–carcinoma sequence in a Portuguese cohort.
The gut microbiome has gained increasing attention in colorectal cancer research, particularly because certain microbial alterations may have potential as early, non-invasive biomarkers of the disease. It is within this context that, since 2014, the researcher has been investigating how the gut microbiota changes during the development and progression of colorectal cancer.
The analysis of faecal samples from a Portuguese cohort revealed particularly relevant alterations at the early stages of the disease. Among the main findings was an increased abundance of bacteria belonging to the genus Sutterella, together with a decrease in Parasuterella and Adlercreutzia in individuals with adenomas and/or early-stage colorectal cancer. These bacterial genera and their respective patterns of variation therefore emerge as potential microbial biomarkers for the early detection of the disease, although their use requires validation in larger cohorts.
The study also raises questions about the robustness of Fusobacterium, one of the bacterial genera frequently associated with colorectal cancer and therefore considered a promising biomarker of the disease. However, the results show that this association loses statistical significance when factors such as age, sex and body mass index are taken into account, highlighting the importance of controlling for these variables when identifying robust microbial biomarkers. Comparison with international cohorts also confirmed that microbial signatures are not fully consistent across different populations, further underscoring the need to validate the robustness and discriminatory capacity of potential biomarkers across different populations and geographical settings before considering universal application.
This research highlights the importance of continuing to explore the microbiome as a dynamic and key component of the relationship between the environment and human health. This approach aligns with the mission of Research Cluster 5 – Environmental Monitoring, Health and Risk Assessment at CESAM, which promotes integrated, interdisciplinary and collaborative research in line with the One Health perspective.
The study, published in Frontiers in Microbiology (available at https://doi.org/10.3389/fmicb.2026.1822941), resulted from a collaboration between researchers at the University of Aveiro and Helmholtz Zentrum München, Germany, with the participation of the Local Health Unit of the Aveiro Region (ULSRA; known as Centro Hospitalar do Baixo Vouga, E.P.E. when the study began).
The researchers would like to express their special thanks to the volunteers who consented to participate in the study, as well as to the teams of healthcare professionals from the Surgery, Gastroenterology, Occupational Medicine and Oncology departments at ULSRA, and to the Board of Directors and the Research and Innovation Office, for their contribution and collaboration.