Colorectal Cancer ScreeningGUTBIOME-PTNCT06741293
Improving Colorectal Cancer Early Screening in Portugal: Identification of Gut Microbiome Biomarkers in Stool (GUTBIOME-PT)
An observational study of Colorectal Cancer Screening and Colorectal Cancer (CRC), run by Gulbenkian Institute for Molecular Medicine at 1 site in Portugal.
Trial summary
Colorectal cancer (CRC) is a major public health problem, responsible for 2 million new cases and almost 1 million deaths annually worldwide. In Portugal, as of 2022, CRC is the most common cancer, with 10,575 new cases reported, and the second leading cause of cancer-related mortality, accounting for 4,809 deaths… Read more about this study
- Who is it for?
- Ages 40 to 74 yearsHealthy volunteers can take part
- Conditions the study is for
- Colorectal Cancer Screening, Colorectal Cancer (CRC), Microbiome
- How many people
- 30,000 participants
- Where
- 1 sitePortugal
- Study dates
- 28 Nov 2023to 28 Nov 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 74 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Two different recruiting strategies will be used: * Opportunistic recruitment: recruitment will be conducted in collaboration with the gastroenterology and general medicine departments of partner hospitals in Lisbon. Eligible individuals scheduled for a screening colonoscopy will be informed about the study by an on-site study coordinator. Those willing to participate will sign an informed consent form. * Random recruitment: interested individuals can access detailed information and assess their eligibility by completing an online questionnaire on the study's website. Eligible participants can register and provide informed consent digitally. After registration, participants will be contacted to arrange the delivery of a self-collection kit for stool sample collection.
Who may be able to join
- Ability to provide written informed consent and comply with study procedures
- Reside in the Lisbon Metropolitan Area,, Portugal
- Age from 40 to 74 years
Who cannot join
- Age < 40 years or ≥ 75 years
- Unable to provide informed consent
- Refusal to provide stool samples
- Active oncological disease
- Personal history of CRC
- Personal history of colon adenomas removed in the last 24 months
Show all 12Show fewer
- First-degree family history of CRC
- Previous diagnosis of inflammatory bowel disease (ulcerative colitis, Crohn's disease or indeterminate colitis), inflammatory bowel syndrome, persistent and infectious gastroenteritis, colitis or gastritis, persistent or chronic diarrhoea of unknown aetiology or recurrent infection by Clostridioides difficile
- Severe cardiovascular or heart diseases with medical diagnosis
- Severe renal failure requiring hemodialysis
- Severe lung disease
- Pregnancy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Portugal1 site, 1 recruiting
- Recruiting
Gulbenkian Institute for Molecular Medicine
Lisbon, Lisbon District, 1649-028
Madalena Reis, +351 217999411, madalena.reis@gimm.pt
Ana S Almeida, PhD
About this study
Official title: Improving Colorectal Cancer Early Screening in Portugal: Identification and Validation of Biomarkers of Gut Microbiome in Stool
Colorectal cancer (CRC) is a major public health problem, responsible for 2 million new cases and almost 1 million deaths annually worldwide. In Portugal, as of 2022, CRC is the most common cancer, with 10,575 new cases reported, and the second leading cause of cancer-related mortality, accounting for 4,809 deaths (approximately 14% of all cancer-related deaths). In recent years, there has been an alarming increase in the incidence and mortality of CRC in people <50 years of age.
Early detection is crucial, as survival rates decline sharply from 90% when detected early to just 10% in advanced stages. Non-invasive diagnostic tests, such as the Faecal Immunochemical Test (FIT), have a low sensitivity for early-stage lesions and a high rate of false positives. Therefore, there is an urgent need to improve non-invasive diagnostic methods for the early detection of CRC, as effective screening can prevent it by detecting and removing premalignant lesions.
Recent studies suggest that an altered gut microbiota may confer susceptibility to certain types of cancer. Interestingly, the gut microbiota of patients with adenomas or CRC differs from that of healthy individuals. This study aims to identify gut microbiome biomarkers in faecal samples associated with CRC and/or high-risk adenomas to improve early detection.
Read the detailed description
This study will analyse the gut microbiome in stool samples collected from individuals living in the Lisbon Metropolitan Area, Portugal. Using shotgun metagenomics, the investigators aim to identify microbiome biomarkers associated with the early detection of CRC and the progression of precancerous lesions (adenomas). The identified biomarkers will be tested to develop a non-invasive and highly sensitive screening tool for CRC and precancerous lesions.
Primary Objective:
To identify gut microbiome biomarkers in faecal DNA associated with CRC and/or high-risk adenomas.
Secondary Objectives:
- Establish the correlation between FIT results, faecal microbiome testing and colonoscopy results. ii) Estimate the incidence of CRC in the Lisbon Metropolitan Area among individuals aged 40-74 years, stratified by sex and age group. iii) Analyse associations between clinical data (e.g., clinical history, lifestyle, and dietary habits), faecal microbiome profiles, FIT results, and colonoscopy outcomes, comparing individuals with CRC and/or high-risk adenomas against healthy individuals, for the total sample and by sex and age group; iv) Identify risk factors (e.g., clinical history, lifestyle, dietary habits) associated with CRC development, stratified by sex and age group.
Study Design:
This is an observational, prospective, longitudinal study involving individuals aged 40-74 years residing in the Lisbon Metropolitan Area who voluntarily enrol in the study.
Participants meeting all inclusion criteria and no exclusion criteria (as detailed in the relevant section) will be included. Based on sample size calculations using the Neyman allocation formula and taking as a reference the distribution of the population living in the Lisbon Metropolitan Area (stratified by sex and age groups: 40-49, 50-59, 60-64, 65-69 and 70-74 years), along with assumptions of the overall FIT test prevalence and sensitivity, a total of 30.000 participants will be enrolled.
At baseline, participants will provide a faecal sample within 2 to 10 days of enrolment. Demographic, clinical, and lifestyle data-including age, family history of CRC, personal medical history, smoking habits, physical activity levels, stress, and body mass index (BMI)-will be collected via self-administered questionnaires. Dietary habits and adherence to the Mediterranean diet will be assessed through telephone interviews.
Participants will be followed for six years, with faecal samples collected every 2 years. Clinical and lifestyle data will also be updated every two years throughout the study period.
- Being tested
- No intervention: observational study
- Keywords
- colorectal cancer, microbiome, colorectal cancer screening, biomarkers, metagenomics
- Medical subject headings
- Colorectal Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No intervention: observational studyOther
No intervention: observational study
| Study group | Role | What they receive |
|---|---|---|
| Control group | Healthy participants with a negative colonoscopy result Receives: Other: No intervention: observational study | |
| Colorectal cancer | Participants with colorectal cancer diagnosis confirmed by colonoscopy Receives: Other: No intervention: observational study | |
| Low-risk polyps | Participants with positive colonoscopy and detection of low-risk adenomas Receives: Other: No intervention: observational study | |
| High-risk polyps | Participants with positive colonoscopy and detection of high-risk adenomas Receives: Other: No intervention: observational study |
What is being measured
The primary outcome is the main question the study is designed to answer.
Microbiome biomarkers associated with CRC and/or high-risk polyps.
The faecal microbiota composition and gene profiles will be analysed using shotgun metagenomic sequencing on a subset of participants (up to 10,000 samples). Data will be integrated with lifestyle, dietary factors and colonoscopy results to identify biomarkers linked to CRC and adenomas.
Measured: Baseline and Follow-up every 2 years up to 6 years
Correlation between microbiome biomarkers and FIT results
Faecal microbiome analysis results will be compared with FIT test results to evaluate the predictive value, negative predictive value, and overall effectiveness in detecting CRC in an asymptomatic population.
Measured: Baseline and Follow-up every 2 years up to 6 years
Secondary outcomes (6)
Effect of diet on CRC risk and gut microbiota composition
Dietary intake will be assessed via telephone interview through two 24-hour recalls, following the protocol validated by the European Food Safety Authority (EFSA).
Measured: Baseline
Effect of the Mediterranean Diet on CRC risk and gut microbiota composition
Adherence to the Mediterranean Diet will be assessed using the PREvención con DIeta MEDiterránea (PREDIMED) nutritional questionnaire, a validated 14-item tool. Each question is scored either 0 (condition not met) or 1 (condition met), resulting in a total score ranging from 0 to 14 (7). Based on this final score, adherence to the Mediterranean Diet will then be categorised into three groups: low adherence (score < 5), moderate adherence (score 6-9), and high adherence (score > 10)
Measured: Baseline
Effect of physical activity on CRC risk and gut microbiota composition
Physical activity will be assessed using the Nordic Physical Activity Questionnaire-short form, a validated tool composed of two close-ended questions for monitoring adherence to WHO physical activity recommendations. Participants will be categorized as "Below WHO physical activity recommendations" or "Equal to WHO physical activity recommendations"
Measured: Baseline
Effect of sleeping habits on CRC risk and gut microbiota composition
Sleeping habits will be assessed by the Pittsburgh Sleep Quality Index (PSQI), a validated questionnaire that consists of 19 items which are distributed into seven "components": subjective sleep quality; sleep latency; sleep duration; habitual sleep efficiency; sleep disturbances; use of sleeping medication; day-time dysfunction. Each component is scored from 0 a 2, and the sum of the component scores yields a global PSQI score. A global PSQI score ≥6 will indicate poor sleep quality.
Measured: Baseline
Effect of stress levels on CRC risk and gut microbiota composition
Stress levels will be assessed by the Perceived Stress Scale, a validated questionnaire composed of 10 questions. Individual scores on the PSS can range from 0 to 40 with higher scores indicating higher perceived stress. Scores ranging from 0-13 will be considered low stress, 14-26 will be considered moderate stress and scores ranging from 27-40 will be considered high perceived stress.
Measured: Baseline
Risk factors (medical history, lifestyle and dietary habits) associated with CRC and/or high-risk polyps
Eligible participants will be invited to participate every two years over six years. Longitudinal data will identify significant risk factors for the development of CRC or high-risk polyps.
Measured: Baseline and Follow-up every 2 years up to 6 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Dec 2024
- Study start28 Nov 2023
- Primary completion28 Nov 2026 (estimated)
- Study completion28 Nov 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colorectal Cancer ScreeningStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 30,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gulbenkian Institute for Molecular Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- Hospital CUF Descobertas, Lisbon, Portugal, CUF Tejo Hospital, Hospital da Luz Lisboa, Portugal
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06741293
- Sponsor's protocol ID
- CAML Ref Nº: 111/23
- Other IDs
- 101060102
- Acronym
- GUTBIOME-PT
- Status last verified
- May 2026
- First submitted
- 10 Dec 2024
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Improving Colorectal Cancer Early Screening in Portugal: Identification and Validation of Biomarkers of Gut Microbiome in Stool
- ClinicalTrials.gov ID
- NCT06741293
- Acronym / sponsor ID
- GUTBIOME-PT / CAML Ref Nº: 111/23
- Keywords
- colorectal cancer, microbiome, colorectal cancer screening, biomarkers, metagenomics
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30,000 participants (estimated)
- Lead sponsor
- Gulbenkian Institute for Molecular MedicineUniversity, hospital or other
- Collaborators
- Hospital CUF Descobertas, Lisbon, Portugal, CUF Tejo Hospital, Hospital da Luz Lisboa, Portugal
- Study start
- 28 Nov 2023 (actual)
- Primary completion
- 28 Nov 2026 (estimated)
- Study completion
- 28 Nov 2029 (estimated)
- First posted
- 18 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Colorectal cancer (CRC) is a major public health problem, responsible for 2 million new cases and almost 1 million deaths annually worldwide. In Portugal, as of 2022, CRC is the most common cancer, with 10,575 new cases reported, and the second leading cause of cancer-related mortality, accounting for 4,809 deaths (approximately 14% of all cancer-related deaths). In recent years, there has been an alarming increase in the incidence and mortality of CRC in people <50 years of age.
Early detection is crucial, as survival rates decline sharply from 90% when detected early to just 10% in advanced stages. Non-invasive diagnostic tests, such as the Faecal Immunochemical Test (FIT), have a low sensitivity for early-stage lesions and a high rate of false positives. Therefore, there is an urgent need to improve non-invasive diagnostic methods for the early detection of CRC, as effective screening can prevent it by detecting and removing premalignant lesions.
Recent studies suggest that an altered gut microbiota may confer susceptibility to certain types of cancer. Interestingly, the gut microbiota of patients with adenomas or CRC differs from that of healthy individuals. This study aims to identify gut microbiome biomarkers in faecal samples associated with CRC and/or high-risk adenomas to improve early detection.
Detailed description
This study will analyse the gut microbiome in stool samples collected from individuals living in the Lisbon Metropolitan Area, Portugal. Using shotgun metagenomics, the investigators aim to identify microbiome biomarkers associated with the early detection of CRC and the progression of precancerous lesions (adenomas). The identified biomarkers will be tested to develop a non-invasive and highly sensitive screening tool for CRC and precancerous lesions.
Primary Objective:
To identify gut microbiome biomarkers in faecal DNA associated with CRC and/or high-risk adenomas.
Secondary Objectives:
- Establish the correlation between FIT results, faecal microbiome testing and colonoscopy results. ii) Estimate the incidence of CRC in the Lisbon Metropolitan Area among individuals aged 40-74 years, stratified by sex and age group. iii) Analyse associations between clinical data (e.g., clinical history, lifestyle, and dietary habits), faecal microbiome profiles, FIT results, and colonoscopy outcomes, comparing individuals with CRC and/or high-risk adenomas against healthy individuals, for the total sample and by sex and age group; iv) Identify risk factors (e.g., clinical history, lifestyle, dietary habits) associated with CRC development, stratified by sex and age group.
Study Design:
This is an observational, prospective, longitudinal study involving individuals aged 40-74 years residing in the Lisbon Metropolitan Area who voluntarily enrol in the study.
Participants meeting all inclusion criteria and no exclusion criteria (as detailed in the relevant section) will be included. Based on sample size calculations using the Neyman allocation formula and taking as a reference the distribution of the population living in the Lisbon Metropolitan Area (stratified by sex and age groups: 40-49, 50-59, 60-64, 65-69 and 70-74 years), along with assumptions of the overall FIT test prevalence and sensitivity, a total of 30.000 participants will be enrolled.
At baseline, participants will provide a faecal sample within 2 to 10 days of enrolment. Demographic, clinical, and lifestyle data-including age, family history of CRC, personal medical history, smoking habits, physical activity levels, stress, and body mass index (BMI)-will be collected via self-administered questionnaires. Dietary habits and adherence to the Mediterranean diet will be assessed through telephone interviews.
Participants will be followed for six years, with faecal samples collected every 2 years. Clinical and lifestyle data will also be updated every two years throughout the study period.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Control group | – | Other: No intervention: observational studyHealthy participants with a negative colonoscopy result |
| Colorectal cancer | – | Other: No intervention: observational studyParticipants with colorectal cancer diagnosis confirmed by colonoscopy |
| Low-risk polyps | – | Other: No intervention: observational studyParticipants with positive colonoscopy and detection of low-risk adenomas |
| High-risk polyps | – | Other: No intervention: observational studyParticipants with positive colonoscopy and detection of high-risk adenomas |
Who may qualify
- Ages
- 40 to 74 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Two different recruiting strategies will be used: * Opportunistic recruitment: recruitment will be conducted in collaboration with the gastroenterology and general medicine departments of partner hospitals in Lisbon. Eligible individuals scheduled for a screening colonoscopy will be informed about the study by an on-site study coordinator. Those willing to participate will sign an informed consent form. * Random recruitment: interested individuals can access detailed information and assess their eligibility by completing an online questionnaire on the study's website. Eligible participants can register and provide informed consent digitally. After registration, participants will be contacted to arrange the delivery of a self-collection kit for stool sample collection.
Key inclusion criteria (3 listed)
- Ability to provide written informed consent and comply with study procedures
- Reside in the Lisbon Metropolitan Area,, Portugal
- Age from 40 to 74 years
Key exclusion criteria (12 listed)
- Age < 40 years or ≥ 75 years
- Unable to provide informed consent
- Refusal to provide stool samples
- Active oncological disease
- Personal history of CRC
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No intervention: observational studyNo intervention: observational study | Other | Colorectal cancer, Control group, High-risk polyps, Low-risk polyps |
Primary outcome
Microbiome biomarkers associated with CRC and/or high-risk polyps.
Time frame: Baseline and Follow-up every 2 years up to 6 years
The faecal microbiota composition and gene profiles will be analysed using shotgun metagenomic sequencing on a subset of participants (up to 10,000 samples). Data will be integrated with lifestyle, dietary factors and colonoscopy results to identify biomarkers linked to CRC and adenomas.
Correlation between microbiome biomarkers and FIT results
Time frame: Baseline and Follow-up every 2 years up to 6 years
Faecal microbiome analysis results will be compared with FIT test results to evaluate the predictive value, negative predictive value, and overall effectiveness in detecting CRC in an asymptomatic population.
6 secondary outcomes
Effect of diet on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of the Mediterranean Diet on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of physical activity on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of sleeping habits on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of stress levels on CRC risk and gut microbiota composition
Time frame: Baseline
Risk factors (medical history, lifestyle and dietary habits) associated with CRC and/or high-risk polyps
Time frame: Baseline and Follow-up every 2 years up to 6 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Public study websiteLink provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Colorectal Cancer Screening and Colorectal Cancer (CRC), run by Gulbenkian Institute for Molecular Medicine at 1 site in Portugal.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ana S Almeida, PhD (+351 217999411, ana.almeida@gimm.pt), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Microbiome biomarkers associated with CRC and/or high-risk polyps. (time frame: Baseline and Follow-up every 2 years up to 6 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.