Effect of Preoperative Diet on Perioperative Gut Microbiome

Can Low-fat/high-fiber or Fermented Diet Modulate the Gut Microbiome to Improve Surgical Outcomes?

The aim of the study is to evaluate the gut microbiome (i.e. bacteria, viruses, and fungi that reside in the gut) of people undergoing abdominal surgery, evaluate whether specific diets can change the gut microbiome, and, if so, whether those changes translate into better surgical outcomes.

Study Overview

• Status: Active, not recruiting
• Conditions: Surgical Site Infection
• Intervention / Treatment: Behavioral: high-fiber/low fat; Behavioral: fermented

Detailed Description

Standard of care: patients undergoing major abdominal colorectal surgery are sometimes advised to eat healthfully prior to surgery, but without more specific recommendations regarding their diet.

Research Activities:

1. Screening: eligible patients will be identified through screening the clinic schedules.
2. Enrollment: in person or remotely, after the patient is determined to require major abdominal surgery, they will be invited to participate in the study. If they consent to participate, they will be randomized to receive either low-fat/high-fiber diet, high-fermented diet, or continue with their normal diet for 10-14 days prior to the surgery.

3. Intervention: at baseline, data will be collected regarding clinical information of the patients (age, body mass index, comorbidities, medications or supplements, physical activity levels, antibiotic or probiotic use in the past six months), and baseline dietary pattern, which will be evaluated through application of a validated Food Frequency Questionnaire (DHQ III). Patients in the intervention arms (low- fat/high-fiber diet or high-fermented diet) will receive meal samples during the 10-14 days preceding surgery. Patients in the control arm will receive a $25 grocery voucher. Adherence to the diet will be assessed through regular check ins with the patients.

   Stool samples will be collected in five timepoints: at the beginning of the study, after the dietary intervention, during surgery, in the first week after the surgery, and between 21-30 days after surgery. The stool samples will be sent for analysis of the microbiome.

   A fragment of the resected bowel will also be sent for analysis of the mucosal-associated microbiome.

4. Closeout: After surgery, all patients will receive the same standard dietary protocol and care, and will be followed for 30 days without any further intervention.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford Health Care

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• undergoing major abdominal colorectal surgery with intestinal resection in 2 or more weeks

Exclusion Criteria:

• patients who do not speak English or Spanish
• houseless patients
• decisionally impaired patients
• presence of ileostomy prior to the surgical procedure
• surgery without intestinal resection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control Arm; Standard care - patients will not receive specific dietary advice.
Experimental: High Fiber/low fat; Patients will receive sample meals and education/support, will be asked to follow this diet for 10 days.	Behavioral: high-fiber/low fat; high fiber/low fat preoperative diet
Experimental: Fermented; Patients will receive sample meals and education/support, will be asked to follow this diet for 10 days.	Behavioral: fermented; fermented preoperative diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in gut microbiome alpha and beta diversity according to pre-operative diet intervention	Metagenomic sequencing will be performed on stool samples before and after dietary change.	Two weeks prior to surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in gut microbiome alpha and beta diversity after surgery according to pre-operative diet	Metagenomic sequencing will be performed on stool samples collected in the first week after surgery and 30 days after surgery	Surgery date until 1 month after surgery
Frequency and severity of surgical complications according to pre-operative diet	Comprehensive Complication Index (CCI) score will be used to measure number and severity of surgical complications occurring within 30 days after surgery. Comprehensive Complication Index score includes minimum value of 0 and maximum value of 100; higher score means higher severity of complication(s).	30 days after surgery

Collaborators and Investigators

• Sponsor: Stanford University

Publications and helpful links

General Publications

• Slankamenac K, Nederlof N, Pessaux P, de Jonge J, Wijnhoven BP, Breitenstein S, Oberkofler CE, Graf R, Puhan MA, Clavien PA. The comprehensive complication index: a novel and more sensitive endpoint for assessing outcome and reducing sample size in randomized controlled trials. Ann Surg. 2014 Nov;260(5):757-62; discussion 762-3. doi: 10.1097/SLA.0000000000000948.
• Wastyk HC, Fragiadakis GK, Perelman D, Dahan D, Merrill BD, Yu FB, Topf M, Gonzalez CG, Van Treuren W, Han S, Robinson JL, Elias JE, Sonnenburg ED, Gardner CD, Sonnenburg JL. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021 Aug 5;184(16):4137-4153.e14. doi: 10.1016/j.cell.2021.06.019. Epub 2021 Jul 12.
• Kok DE, Arron MNN, Huibregtse T, Kruyt FM, Bac DJ, van Halteren HK, Kouwenhoven EA, Wesselink E, Winkels RM, van Zutphen M, van Duijnhoven FJB, de Wilt JHW, Kampman E. Association of Habitual Preoperative Dietary Fiber Intake With Complications After Colorectal Cancer Surgery. JAMA Surg. 2021 Jun 16;156(9):1-10. doi: 10.1001/jamasurg.2021.2311. Online ahead of print.
• Hyoju SK, Adriaansens C, Wienholts K, Sharma A, Keskey R, Arnold W, van Dalen D, Gottel N, Hyman N, Zaborin A, Gilbert J, van Goor H, Zaborina O, Alverdy JC. Low-fat/high-fibre diet prehabilitation improves anastomotic healing via the microbiome: an experimental model. Br J Surg. 2020 May;107(6):743-755. doi: 10.1002/bjs.11388. Epub 2019 Dec 26.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2022
• Primary Completion (Estimated): June 1, 2025
• Study Completion (Estimated): September 20, 2025

Study Registration Dates

• First Submitted: August 17, 2021
• First Submitted That Met QC Criteria: August 25, 2021
• First Posted (Actual): August 30, 2021

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 19, 2025
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Postoperative Complications; Pathologic Processes; Infections; Wound Infection; Surgical Wound Infection
• Other Study ID Numbers: 62330

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No