Effects of eating fermented vegetables on gut health

Fermented Vegetables and Gut Microbiome Pilot Study

This study tests whether eating fermented vegetables can improve gut health and how well healthy adults aged 18 to 65 can handle this change in their diet.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 24 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: USDA, Western Human Nutrition Research Center (Federal)
• Drugs / interventions: radiation, prednisone
• Locations: 1 site (Davis, California)
• Trial ID: NCT06883994 on ClinicalTrials.gov

What this trial studies

This research aims to evaluate how consuming fermented vegetables affects the abundance of lactic acid bacteria (LAB) in the gut and the tolerability of this dietary intervention among healthy adults aged 18 to 65. The study will assess various gastrointestinal symptoms, stool consistency, and frequency, as well as immune function indicators like salivary sIgA levels. By gathering data on these factors, the study seeks to inform the design of a larger randomized controlled trial focused on the impact of fermented vegetables on gut microbiome composition and overall gut health.

Who should consider this trial

Good fit: Ideal candidates are non-obese adults aged 18 to 65 with a BMI between 18.5 and 39.9 kg/m2.

Not a fit: Patients with high blood pressure, dietary restrictions against fermented vegetables, or certain medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of how fermented vegetables improve gut health and immune function.

How similar studies have performed: Previous studies have shown positive effects of fermented foods on gut health, but this specific focus on fermented vegetables is relatively novel.

Eligibility criteria

We will enroll non-obese adults aged 18-65 years, with BMI between 18.5 and 39.9 kg/m2. We will exclude people with a high blood pressure, who cannot consume fermented vegetables, and those among whom a medical condition, use of medication, use of probiotic supplements or consumption of fermented foods may influence trial outcomes. Those who are uncomfortable with the stool sample collection protocol, or who may not be able to complete the stool samples due to infrequent bowel movements, will also be excluded.

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.

Inclusion Criteria:

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

Exclusion Criteria:

* 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

Where this trial is running

Davis, California

• USDA Western Human Nutrition Research Center — Davis, California, United States (Recruiting)

Study contacts

• Principal investigator: Danielle G Lemay, PhD — USDA, Western Human Nutrition Research Center
• Study coordinator: Danielle G Lemay, PhD

Conditions Fermented Vegetable Intake; Fermented Vegetable Acceptability; Gut Health; Gut Microbiome; Gastrointestinal Immune Function; Microbiome; Fermented vegetables; Fermented foods