Surgical Site InfectionNCT05027763
Effect of Preoperative Diet on Perioperative Gut Microbiome
A study testing high-fiber and fermented in people with Surgical Site Infection, run by Stanford University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Surgical Site Infection
- What is being tested?
- high-fiber and fermented
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Mar 2022to 13 Nov 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- undergoing major abdominal colorectal surgery with intestinal resection in 2 or more weeks
Who cannot join
- no access to smartphone
- patients who do not speak English or Spanish
- houseless patients
- decisionally impaired patients
- presence of ileostomy prior to the surgical procedure
- creation of end ileostomy at the time of procedure
- surgery without intestinal resection
- baseline consumption of more than 20g of fiber per ay, or more than 2 servings of fermented food per day
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Can 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.
Read the 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:
- Screening: eligible patients will be identified through screening the clinic schedules.
- 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 high-fiber diet, high-fermented diet, or continue with their normal diet for 10-14 days prior to the surgery.
- 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 (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.
- 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.
- Conditions
- Surgical Site Infection
- Being tested
- high-fiber, fermented
- Medical subject headings
- Surgical Wound Infection
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
high-fiberBehavioural
high fiber preoperative diet
fermentedBehavioural
fermented preoperative diet
| Study group | Role | What they receive |
|---|---|---|
| Control Arm | No intervention | Standard care - patients will not receive specific dietary advice. |
| High Fiber | Experimental | Patients will receive sample meals and education/support, will be asked to follow this diet for 10-14 days. Receives: Behavioral: high-fiber |
| Fermented | Experimental | Patients will receive sample meals and education/support, will be asked to follow this diet for 10-14 days. Receives: Behavioral: fermented |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Two weeks prior to surgery
Secondary outcomes (2)
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
Measured: 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).
Measured: 30 days after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Aug 2021
- Study start11 Mar 2022
- Primary completion2 Nov 2024
- Study completion13 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Surgical Site InfectionStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Care provider, Outcomes assessor
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Cindy Kin, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05027763
- Sponsor's protocol ID
- 62330
- Status last verified
- Mar 2024
- First submitted
- 17 Aug 2021
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
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.
PubMed 31879948Kok 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.
PubMed 34132738Wastyk 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.
PubMed 34256014Slankamenac 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.
PubMed 25379846
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Can High-fiber or Fermented Diet Modulate the Gut Microbiome to Improve Surgical Outcomes?
- ClinicalTrials.gov ID
- NCT05027763
- Acronym / sponsor ID
- 62330
- Conditions
- Surgical Site Infection
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- 11 Mar 2022 (actual)
- Primary completion
- 2 Nov 2024 (actual)
- Study completion
- 13 Nov 2024 (actual)
- First posted
- 30 Aug 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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:
- Screening: eligible patients will be identified through screening the clinic schedules.
- 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 high-fiber diet, high-fermented diet, or continue with their normal diet for 10-14 days prior to the surgery.
- 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 (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.
- 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 design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (care provider, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Control Arm | No intervention | –Standard care - patients will not receive specific dietary advice. |
| High Fiber | Experimental | Behavioral: high-fiberPatients will receive sample meals and education/support, will be asked to follow this diet for 10-14 days. |
| Fermented | Experimental | Behavioral: fermentedPatients will receive sample meals and education/support, will be asked to follow this diet for 10-14 days. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- undergoing major abdominal colorectal surgery with intestinal resection in 2 or more weeks
Key exclusion criteria (8 listed)
- no access to smartphone
- patients who do not speak English or Spanish
- houseless patients
- decisionally impaired patients
- presence of ileostomy prior to the surgical procedure
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| high-fiberhigh fiber preoperative diet | Behavioural | High Fiber |
| fermentedfermented preoperative diet | Behavioural | Fermented |
Primary outcome
Change in gut microbiome alpha and beta diversity according to pre-operative diet intervention
Time frame: Two weeks prior to surgery
Metagenomic sequencing will be performed on stool samples before and after dietary change.
2 secondary outcomes
Change in gut microbiome alpha and beta diversity after surgery according to pre-operative diet
Time frame: Surgery date until 1 month after surgery
Frequency and severity of surgical complications according to pre-operative diet
Time frame: 30 days after surgery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
- Background: PubMed 31879948Hyoju 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.
- Background: PubMed 34132738Kok 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.
- Background: PubMed 34256014Wastyk 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.
- Background: PubMed 25379846Slankamenac 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing high-fiber and fermented in people with Surgical Site Infection, run by Stanford University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in gut microbiome alpha and beta diversity according to pre-operative diet intervention (time frame: Two weeks prior to surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05027763, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026.