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

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

Status
Completed
Phases
Early Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05658263
Enrollment
14
Registered
2022-12-20
Start date
2023-01-03
Completion date
2024-08-15
Last updated
2025-05-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Colon Cancer, Dysbiosis, Sarcopenia

Brief summary

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.

Interventions

DIETARY_SUPPLEMENTStandard 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_SUPPLEMENTBIG 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.

Sponsors

University of Minnesota
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
25 Years to 70 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Compliance with the dietary intervention or standard of care- survey4 weeks24-hour diet recall surveys conducted by Nutrition Coordinating Center at University of Minnesota
Frequency of accidental mucus leakage4 weeks after surgerythis will be assessed in times per day or times per month
Frequency of accidental liquid stool leakage4 weeks after surgerythis will be assessed in times per day or times per month
Frequency of bowel movements4 weeks after surgerythis will be assessed in numbers per day or numbers per week
stool consistency4 weeks after surgeryBristol Stool Chart: Type 1 (hard lumps) through Type 7 (watery, no solid pieces, entirely liquid
Bowel emptying patterns4 weeks after surgery(includes constipation, diarrhea, urgency; range: always--\> never)
Laxative/stool softener use4 weeks after surgeryYes/No
Gastrointestinal comfort24 hours before surgeryrange: 0 (no problem) --\> 4 (very strong discomfort)
Compliance with the dietary intervention or standard of care- Baseline veggie meterbaselinecarotenoid score, triplicate measurement; range: 0 (lower estimated value)-800 (arbitrary units; higher estimated value correlates with greater carotenoid concentrations
Change in muscle massbaseline and 4 weeks after surgeryThe 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.
Frequency of accidental gas leakage4 weeks after surgerythis will be assessed in times per day or times per month

Secondary

MeasureTime frameDescription
Change in microbiome features- beta diversityBaseline, time of surgery, postop day 7 and 30compositionally corrected Aitchison's distances
Fecal metabolitesbaseline and 4 weeks after surgeryTargeted fecal and serum metabolomics will measure changes in short chain fatty acids (SCFAs) and bile acids.
Fecal inflammatory markersBaseline and 4 weeks after surgeryELISA. Fecal calprotectin and IgA levels will be measured using ELISA as markers of intestinal inflammation.
Changes in body composition- abdominal muscleBaseline, time of surgery, postop day 7 and 30total 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
Changes in body composition- psoas muscleBaseline, time of surgery, postop day 7 and 30total 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
Changes in body composition- volume of fatBaseline, time of surgery, postop day 7 and 30MRI-measured area (cm2) and volume (L) of subcutaneous and visceral adipose tissue
Changes in body composition- liver fatBaseline, time of surgery, postop day 7 and 30MRI-measured liver fat content
Change in microbiome features- alpha diversityBaseline, time of surgery, postop day 7 and 30Shannon, Simpson, and Chao1 indices

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026