Bacterial Intestinal Gut Modification Around Cancer Surgery (BIG MACS) Diet

May 12, 2025 updated by: University of Minnesota
The long-term study objective is to develop optimized nutritional therapies for surgery and test them in clinical practice. This pilot study will test a microbiome-optimization diet in colorectal cancer surgery patients. The study hypothesizes that the Bacterial Intestinal Gut Modification Around Cancer Surgery (BIG MACS) Diet will provide participants with increased microbiota accessible carbohydrates (MACs) to support the microbiome and improve outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
14

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Minnesota
      • Minneapolis, Minnesota, United States, 55455
        • University of Minnesota

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

25 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 25-70 years
  • Primary diagnosis of colon cancer, stages 1-3.
  • Able and willing to provide informed consent.
  • English-speaking.
  • Willingness to return to the study site for specified study visits at D7 and D30.
  • Able to comply with study measures.

Exclusion Criteria:

  • Age ≤ 25 years or ≥70 years
  • If surgery is being performed for any reason other than resection of colon cancer. Neoadjuvant therapy, or if surgery is not the initial approach for the patient's colon cancer treatment
  • Significant anemia (hemoglobin 1.0 g/dL or more below normal range) or history of coagulopathy: any personal history of hereditary or acquired bleeding disorder, or thrombocytopenia with platelets under 100,000.
  • Serum creatinine greater than 1.5 mg/dL.
  • Serum total bilirubin greater than the upper limit of normal in the absence of Gilbert's syndrome or alkaline phosphatase or ALT or AST greater than 2.5 times the upper limit of normal. Elevated INR (1.5 or above).
  • Alcohol intake more than one drink or greater than 20 grams per day for women or 30 grams per day for men.
  • History of gastrointestinal surgery including stomach, small bowel or colon resection, pancreatic surgery, bile duct or gallbladder surgery, or splenectomy, or gastric bypass.
  • History of intra-abdominal sepsis.
  • Previous organ transplantation.
  • Self-reported HIV-positive status, active tuberculosis, active malaria, chronic hepatitis B or C, cirrhosis, or inflammatory bowel disease.
  • Currently pregnant or nursing.
  • History of alcohol, drug, or opioid dependency (excluding nicotine) in the past five years.
  • Active psychosocial or psychiatric problem that is likely to interfere with adherence to the protocol.
  • Depression: A CES-D score more than 16 and a psychologist determining that the patient is not a good fit for surgery.
  • Body mass index (BMI) <20 or > 40 kilograms per meter squared:

obesity is known to impact the microbiome and immune system and the occurrence of anastomotic leak, and extreme obesity may confound interpretation of these factors in association to leak. Inferences may be made by matching participants with less severe obesity (BMI <40).

  • Presence of any type of non-MRI compatible implant, including cardiac pacemakers or defibrillators, neurostimulators, cochlear implants, or other metallic hardware
  • Self-reported history of claustrophobia.
  • Incarceration
  • Inability to adhere to the study protocol, procedures, and diet
  • Exclusions may also be made at the discretion of the attending physician.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Standard Diet
Participants receiving only standard of care (SOC) nutrition advice, which is SOC Dietary Instructions, as provided by routine surgical consults and one protein shake per day for 4 weeks prior to surgery (SOC).
Dietary supplement: Standard Diet
Participants receiving only standard of care (SOC) nutrition advice, which is SOC Dietary Instructions, as provided by routine surgical consults and one protein shake per day for 4 weeks prior to surgery (SOC).
Experimental: BIG MACS Diet
Participants will be instructed to consume the study diet, referred to as the 'BIG MACS Diet' and one protein shake per day for 4 weeks prior to surgery (SOC). Following surgery, participants will continue to follow the BIG MACS Diet for an additional four weeks, with solid food reintroduction after surgery as early as tolerated.
Dietary supplement: BIG MACS Diet
Participants will be instructed to consume the study diet, referred to as the 'BIG MACS Diet' and one protein shake per day for 4 weeks prior to surgery (SOC). Following surgery, participants will continue to follow the BIG MACS Diet for an additional four weeks, with solid food reintroduction after surgery as early as tolerated.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in muscle mass
Time Frame: baseline and 4 weeks after surgery
The change in muscle mass assessed by MRI-measured area and density of the psoas muscle at the level of the L3 vertebra with adjunct grip strength measurement.
baseline and 4 weeks after surgery
Frequency of accidental gas leakage
Time Frame: 4 weeks after surgery
this will be assessed in times per day or times per month
4 weeks after surgery
Frequency of accidental mucus leakage
Time Frame: 4 weeks after surgery
this will be assessed in times per day or times per month
4 weeks after surgery
Frequency of accidental liquid stool leakage
Time Frame: 4 weeks after surgery
this will be assessed in times per day or times per month
4 weeks after surgery
Frequency of bowel movements
Time Frame: 4 weeks after surgery
this will be assessed in numbers per day or numbers per week
4 weeks after surgery
stool consistency
Time Frame: 4 weeks after surgery
Bristol Stool Chart: Type 1 (hard lumps) through Type 7 (watery, no solid pieces, entirely liquid
4 weeks after surgery
Bowel emptying patterns
Time Frame: 4 weeks after surgery
(includes constipation, diarrhea, urgency; range: always--> never)
4 weeks after surgery
Laxative/stool softener use
Time Frame: 4 weeks after surgery
Yes/No
4 weeks after surgery
Laxative/stool softener use
Time Frame: 4 weeks after surgery
times/day
4 weeks after surgery
Laxative/stool softener use
Time Frame: 4 weeks after surgery
times/week
4 weeks after surgery
Laxative/stool softener use
Time Frame: 4 weeks after surgery
times/month
4 weeks after surgery
Gastrointestinal comfort
Time Frame: 24 hours before surgery
range: 0 (no problem) --> 4 (very strong discomfort)
24 hours before surgery
Bowel emptying patterns
Time Frame: 24 hours before surgery
includes constipation, diarrhea, urgency; range: 0 (never) --> 4 (always)
24 hours before surgery
Laxative/stool softener use
Time Frame: 24 hours before surgery
range; 0-4+ doses
24 hours before surgery
Compliance with the dietary intervention or standard of care- Baseline veggie meter
Time Frame: baseline
carotenoid score, triplicate measurement; range: 0 (lower estimated value)-800 (arbitrary units; higher estimated value correlates with greater carotenoid concentrations
baseline
Compliance with the dietary intervention or standard of care- Baseline veggie meter
Time Frame: postop day 7
carotenoid score, triplicate measurement; range: 0 (lower estimated value)-800 (arbitrary units; higher estimated value correlates with greater carotenoid concentrations
postop day 7
Compliance with the dietary intervention or standard of care- Baseline veggie meter
Time Frame: postop day 30
carotenoid score, triplicate measurement; range: 0 (lower estimated value)-800 (arbitrary units; higher estimated value correlates with greater carotenoid concentrations
postop day 30
Compliance with the dietary intervention or standard of care- survey
Time Frame: 4 weeks
24-hour diet recall surveys conducted by Nutrition Coordinating Center at University of Minnesota
4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in microbiome features- alpha diversity
Time Frame: Baseline, time of surgery, postop day 7 and 30
Shannon, Simpson, and Chao1 indices
Baseline, time of surgery, postop day 7 and 30
Change in microbiome features- beta diversity
Time Frame: Baseline, time of surgery, postop day 7 and 30
compositionally corrected Aitchison's distances
Baseline, time of surgery, postop day 7 and 30
Fecal metabolites
Time Frame: baseline and 4 weeks after surgery
Targeted fecal and serum metabolomics will measure changes in short chain fatty acids (SCFAs) and bile acids.
baseline and 4 weeks after surgery
Fecal inflammatory markers
Time Frame: Baseline and 4 weeks after surgery
ELISA. Fecal calprotectin and IgA levels will be measured using ELISA as markers of intestinal inflammation.
Baseline and 4 weeks after surgery
Changes in body composition- abdominal muscle
Time Frame: Baseline, time of surgery, postop day 7 and 30
total abdominal muscle area in cm squared. Absolute and relative change in total abdominal muscle area per patient over time (cm squared ), with the average change per patient group compared between study and control group
Baseline, time of surgery, postop day 7 and 30
Changes in body composition- psoas muscle
Time Frame: Baseline, time of surgery, postop day 7 and 30
total psoas muscle area in cm squared. Absolute and relative change in total psoas muscle area per patient over time (cm squared ), with the average change per patient group compared between study and control group
Baseline, time of surgery, postop day 7 and 30
Changes in body composition- volume of fat
Time Frame: Baseline, time of surgery, postop day 7 and 30
MRI-measured area (cm2) and volume (L) of subcutaneous and visceral adipose tissue
Baseline, time of surgery, postop day 7 and 30
Changes in body composition- liver fat
Time Frame: Baseline, time of surgery, postop day 7 and 30
MRI-measured liver fat content
Baseline, time of surgery, postop day 7 and 30

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Minnesota

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Cyrus Jahansouz, University of Minnesota

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 3, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 15, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 15, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 11, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 19, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 20, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 13, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 12, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SURG-2023-31051

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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