NCT05692024 · Massachusetts General Hospital
COffee and Metabolites Modulating the Gut MicrobiomE in Colorectal caNCER
(COMMENCER)
What this study is about
This is research study is assessing the effects of 6-g daily use of freeze-dried instant coffee on liver fat and fibrosis and the gut microbiome and metabolome in patients who have completed routine treatment (including surgery, chemotherapy and radiotherapy) for stage I-III colorectal cancer.
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This is research study is assessing the effects of 6-g daily use of freeze-dried instant coffee on liver fat and fibrosis and the gut microbiome and metabolome in patients who have completed routine treatment (including surgery, chemotherapy and radiotherapy) for stage I-III colorectal cancer.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants must meet the following criteria on screening examination to be eligible to participate in the study:
- Participants must have histologically confirmed stage I, II, or III colon or rectal adenocarcinoma and have completed standard treatment (including surgery, chemotherapy and radiotherapy) at least 2 months ago.
- Age 18 years or older.
- This study will only include adult participants because colorectal carcinogenesis in children is more likely to be related to a cancer predisposition syndrome with distinct biological mechanisms compared with sporadic colorectal cancer in adults.
- The effects of coffee on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
- Subjects must be able and willing to follow study procedures and instructions.
- Ability to understand and the willingness to sign a written informed consent document.
Exclusion criteria
- Participants who exhibit any of the following conditions at screening will not be eligible for admission into the study.
- Participants who are receiving any other investigational agents.
- Concurrent use of other anti-cancer therapy, including chemotherapy agents, targeted agents, biological agents, immunotherapy, or investigational agents not otherwise specified in this protocol.
- Regularly consuming more than 2 cups of coffee ( 8 oz) per day for at least 3 days a week in the past month.
- Current or recent use (within 1 month) of any coffee supplements (e.g., green coffee extracts).
- History of diagnosed conditions that may be worsen by coffee, including arrhythmias, insomnia, tremors, tics, generalized anxiety disorder, bipolar disease, panic attacks, Tourette's, epilepsy or overactive bladder.
- History of adverse reactions to coffee or intolerance of coffee consumption.
- Inability or unwillingness to swallow capsules.
- History of malabsorption or uncontrolled vomiting or diarrhea, or any other disease that could interfere with absorption of oral medications.
- Any uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, or psychiatric illness/social situations that, in the opinion of the investigator, may increase the risks associated with study participation or study treatment, limit compliance with study requirements, or interfere with the interpretation of study results.
- Pregnant or breastfeeding. The effects of coffee on the developing human fetus are unknown. For this reason, women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately. Similarly, lactating women are excluded from this study because there is an unknown but potential risk of adverse events in nursing infants secondary to treatment of the mother with coffee. Consequently, breastfeeding should be discontinued if the mother is enrolled on the study.
- Presence of synchronous (at the same time) malignancy for which the patient is currently receiving active treatment.
- Known positive test for human immunodeficiency virus (HIV), hepatitis C virus, or acute or chronic hepatitis B infection.
Where
- Boston, Massachusetts
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 5, 2026 · Source of record for eligibility and locations