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

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: Completed
• Conditions: Sarcopenia; Dysbiosis; Colon Cancer
• Intervention / Treatment: Dietary supplement: Standard Diet; Dietary supplement: BIG MACS Diet

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Early Phase 1

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Change in muscle mass	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	this will be assessed in times per day or times per month	4 weeks after surgery
Frequency of accidental mucus leakage	this will be assessed in times per day or times per month	4 weeks after surgery
Frequency of accidental liquid stool leakage	this will be assessed in times per day or times per month	4 weeks after surgery
Frequency of bowel movements	this will be assessed in numbers per day or numbers per week	4 weeks after surgery
stool consistency	Bristol Stool Chart: Type 1 (hard lumps) through Type 7 (watery, no solid pieces, entirely liquid	4 weeks after surgery
Bowel emptying patterns	(includes constipation, diarrhea, urgency; range: always--> never)	4 weeks after surgery
Laxative/stool softener use	Yes/No	4 weeks after surgery
Laxative/stool softener use	times/day	4 weeks after surgery
Laxative/stool softener use	times/week	4 weeks after surgery
Laxative/stool softener use	times/month	4 weeks after surgery
Gastrointestinal comfort	range: 0 (no problem) --> 4 (very strong discomfort)	24 hours before surgery
Bowel emptying patterns	includes constipation, diarrhea, urgency; range: 0 (never) --> 4 (always)	24 hours before surgery
Laxative/stool softener use	range; 0-4+ doses	24 hours before surgery
Compliance with the dietary intervention or standard of care- Baseline veggie meter	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	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	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	24-hour diet recall surveys conducted by Nutrition Coordinating Center at University of Minnesota	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in microbiome features- alpha diversity	Shannon, Simpson, and Chao1 indices	Baseline, time of surgery, postop day 7 and 30
Change in microbiome features- beta diversity	compositionally corrected Aitchison's distances	Baseline, time of surgery, postop day 7 and 30
Fecal metabolites	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	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	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	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	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	MRI-measured liver fat content	Baseline, time of surgery, postop day 7 and 30

Collaborators and Investigators

• Sponsor: University of Minnesota
• Investigators: Principal Investigator: Cyrus Jahansouz, University of Minnesota

Study record dates

Study Major Dates

• Study Start (Actual): January 3, 2023
• Primary Completion (Actual): August 15, 2024
• Study Completion (Actual): August 15, 2024

Study Registration Dates

• First Submitted: October 11, 2022
• First Submitted That Met QC Criteria: December 19, 2022
• First Posted (Actual): December 20, 2022

Study Record Updates

• Last Update Posted (Actual): May 13, 2025
• Last Update Submitted That Met QC Criteria: May 12, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathologic Processes; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Dysbiosis; Sarcopenia
• Other Study ID 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