Fermented Vegetables and Gut Microbiome Pilot Study

NCT ID: NCT06883994

Last Updated: 2025-12-15

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-03-19
• Study Completion Date: 2025-09-09

Brief Summary

The purpose of this research is to determine the effect of fermented vegetable consumption on LAB abundance and tolerability of the intervention in young healthy people before conducting a full RCT with older participants.

Detailed Description

The purpose of this research is to determine the tolerability of fermented vegetable consumption and its effect on lactic acid bacteria (LAB) abundance in healthy people. There is evidence from previous studies that eating fermented foods containing live microbes can affect the gut microbiome and gut health, but there is little information on the impact of fermented vegetables, specifically.

This research will expand the limited existing literature on the effect of fermented vegetable intake on LAB abundance, GI symptoms, fecal consistency and frequency.

Specific knowledge will be produced regarding the magnitude and variation in the increase in LAB bacterial load during fermented vegetable consumption and whether one week is sufficient for LAB to pass out of the gastrointestinal tract. The effect of fermented vegetable consumption on total salivary sIgA levels in healthy adults will also be determined.

The study will also produce knowledge on whether symptoms of bloating and flatulence will improve with fermented vegetables. Stool consistency, stool frequency, GI symptoms, blood pressure and product acceptability data will inform the study design for a future randomized controlled trial of the effects of fermented vegetables on gut microbiome composition and function, gut health and immune function.

The impacts of fermented vegetable consumption on the human gut microbiome, intestinal permeability, and GI inflammation will also be determined with in vitro experiments.

Conditions

Fermented Vegetable Intake; Fermented Vegetable Acceptability; Gut Health; Gut Microbiome; Gastrointestinal Immune Function; Microbiome

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Fermented vegetable consumption

Participants will complete a 1-week baseline with no fermented food intake, followed by a 4-day fermented vegetable intervention, and then a 1-week follow-up period with no fermented food intake.

Group Type: EXPERIMENTAL

Fermented vegetable intervention

Intervention Type: OTHER

Participants will be provided with reduced-sodium fermented vegetables developed by Dr. Ilenys Pérez-Díaz at the USDA-ARS Food Science and Market Quality and Handling Research Unit. The fermented, refrigerated vegetables have been shown to have Lactiplantibacillus spp. content >10^7 CFU/mL at 21 days shelf-life.

Products are prepared in a Good Manufacturing Practices Facility at North Carolina State University, Department of Food, Bioprocessing, and Nutrition Sciences.

The fermented vegetables will be shipped in coolers on cold packs with temperature indicators to the WHNRC. Participants will be asked to consume two pre-packaged 50g servings of fermented vegetables a day, for a total daily serving of 100g, not to heat the fermented vegetables prior to consumption, to log their consumption and to rate the acceptability of the fermented vegetables. They will be advised to avoid other fermented foods and to otherwise maintain their habitual diet.

Interventions

Fermented vegetable intervention

Participants will be provided with reduced-sodium fermented vegetables developed by Dr. Ilenys Pérez-Díaz at the USDA-ARS Food Science and Market Quality and Handling Research Unit. The fermented, refrigerated vegetables have been shown to have Lactiplantibacillus spp. content >10^7 CFU/mL at 21 days shelf-life.

Products are prepared in a Good Manufacturing Practices Facility at North Carolina State University, Department of Food, Bioprocessing, and Nutrition Sciences.

The fermented vegetables will be shipped in coolers on cold packs with temperature indicators to the WHNRC. Participants will be asked to consume two pre-packaged 50g servings of fermented vegetables a day, for a total daily serving of 100g, not to heat the fermented vegetables prior to consumption, to log their consumption and to rate the acceptability of the fermented vegetables. They will be advised to avoid other fermented foods and to otherwise maintain their habitual diet.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Age 18 - 65 years
• BMI 18.5 - 39.9 kg/m2

Exclusion Criteria

Adults who are unable to consent, individuals who are not yet adults (infants, children, teenagers), pregnant women, and prisoners will be excluded from participation in the study.

• BMI less than 18.5 or greater than 39.9
• Pregnant or breastfeeding
• Allergy or sensitivity to any fruit or vegetable
• Dietary restriction preventing consumption of fermented vegetables
• Consumption of probiotic supplements, foods or drinks in the past month

• Probiotic supplements include any tablets, liquids, powders, chewables or other formulations that provide high-quantity, live probiotic microbes
• Probiotic foods and drinks include products labeled as 'probiotic' because they contain live microbes in types and quantities that may confer a health benefit
• Regular consumption, defined as consumption more than once per week in the past two weeks, of live microbe-containing fermented vegetables or cultured dairy products, such as kimchi, refrigerated fermented pickles, traditional (lacto-fermented) sauerkraut, yogurt, or kefir

• In case of less frequent consumption, defer study start such that baseline assessments are completed at least two weeks after last intake
• Unwillingness to abstain from non-study fermented foods and probiotics during the trial
• Uncomfortable with or unwilling to complete stool sample or saliva collections
• Current participation in another interventional research study
• Having fewer than 3 bowel movements per week
• Unmanaged hypertension, defined as blood pressure greater than or equal to 140/90 mmHg
• Current diagnosis of:

• Disease that affects the immune system or causes immune impairment, including HIV/AIDS
• Cancer
• Diabetes
• Asthma with daily medication
• Primary immune deficiency
• Auto-immune disease
• Chronic gastrointestinal disorder (e.g. Crohn's disease, irritable bowel syndrome, colitis, gastric ulcer)
• Chronic kidney disease
• Current use for 2 weeks or longer of:

• Any drug that affects the immune system, such as immunosuppressants, immune modifying drugs, or corticosteroids (e.g. cortisone, prednisone, methylprednisolone)
• Biologics (e.g. Lantus, Remicade, Rituxan, Humira, Herceptin, Avastin, Lucentis, Enbrel)
• GLP-1 agonists, such as semaglutide and tirzepatide.
• Antidiabetic medications, such as Metformin.
• Diuretics, such as Hydrochlorothiazide
• Use of sulfonamides or antimicrobials, including antibiotics, antifungals, antivirals, and antiparasitic medications in the past 3 months
• Use of laxatives in the past 2 weeks
• Currently undergoing cancer treatment with radiation or drugs
• History of gastrointestinal surgery that would impact study outcomes, such as gastric bypass, intestinal resection, surgeries of the liver or pancreas, or removal of part or all of any organ of the GI tract
• Having within the past 2 weeks:

• Diarrheal illness, defined as passing 3 or more abnormally loose or watery stools in a 24-hour period
• Persistent vomiting
• Fever
• Having within the past 3 months:

• Surgery
• Hospitalization
• Having within the past 1 month:

• Colonoscopy

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

USDA, Western Human Nutrition Research Center

FED

Sponsor Role: lead

Responsible Party

Bess L Caswell

Research Nutritionist

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Danielle G Lemay, PhD

Role: PRINCIPAL_INVESTIGATOR

USDA, Western Human Nutrition Research Center

Bess L Caswell, PhD

Role: PRINCIPAL_INVESTIGATOR

USDA, Western Human Nutrition Research Center

Mary E Kable, PhD

Role: PRINCIPAL_INVESTIGATOR

USDA, Western Human Nutrition Research Center

Locations

USDA Western Human Nutrition Research Center

Davis, California, United States

Countries

United States

Provided Documents

Document Type: Informed Consent Form

View Document

Other Identifiers

USDA 2032-10700-002-000D

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

FL125

Identifier Type: -

Identifier Source: org_study_id