Health BehaviorKOMICSNCT06484504
Effect of Kombucha Consumption on the Microbiome in Healthy Subjects
A study testing Kombucha beverage in people with Health Behavior, run by University of California, San Diego at 1 site in United States.
Trial summary
This proposed pilot study will assess the ability of consumption of two servings of kombucha daily to decrease inflammation, alter the gut microbiome composition, and improve intestinal wellbeing in a free-living population. The primary objective is to determine changes in the fecal microbiome composition. Read more about this study
- Who is it for?
- Ages 21 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Health Behavior
- What is being tested?
- Kombucha beverage
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 31 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Mar 2022to 25 Apr 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 21 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Typically consume low fiber/polyphenol diet (beige diet)
- BMI within 25-29.9 kg/m2
Who cannot join
- Eating a high fiber/polyphenol diet or taking any medication or dietary supplement, which interfere with the absorption of polyphenols
- History of gastrointestinal surgery, diabetes mellitus on medications, or other serious medical condition, such as chronic hepatic or renal disease, bleeding disorder, congestive heart disease, chronic diarrhea disorders, myocardial infarction, coronary artery bypass graft, angioplasty within 6 months prior to screening, current diagnosis of uncontrolled hypertension (defined as systolic BP >160mmHg, diastolic BP > 95mmHg), active or chronic gastrointestinal disorders, bulimia, anorexia, laxative abuse, or endocrine diseases (except thyroid disease requiring medication) as indicated by medical history or routine physical examination
- Is unable or unwilling to comply with the study protocol
- Using prebiotics, probiotics, yogurt, and/or any fiber supplements regularly
- Taking antibiotics or laxatives within the past 3 months
- Allergy or sensitivity to kombucha
- In the opinion of the study investigator, any subject who demonstrate a risk of non-compliance with study procedure, or one who cannot read, understand, or complete study
Trial locations and contacts
1 site in 1 country.
About this study
This proposed pilot study will assess the ability of consumption of two servings of kombucha daily to decrease inflammation, alter the gut microbiome composition, and improve intestinal wellbeing in a free-living population. The primary objective is to determine changes in the fecal microbiome composition. Secondary outcomes will be bacterial metabolites (fecal indole propionic acid, calprotectin), serum interleukin (IL) 6, interleukin (IL) 10, C-reactive protein (CRP), C-peptide, insulin, fasting glucose, Homeostatic Model Assessment for Insulin Resistance (HOMA), 14-day continuous glucose monitor, digestive health, dietary information, general Health \& Wellness at 4 and 8 weeks.
Read the detailed description
An altered intestinal gut microbiota, i.e. dysbiosis, has been associated with the development of intestinal disease including inflammatory bowel disease and metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disease. Fermented foods such as Kefir, Kombucha, Miso, and Kimchi contain potentially probiotic microorganisms. The characteristic microbiome in kombucha includes several genera of acetic acid bacteria, yeasts and lactic acid bacteria. Interactions between bacteria and yeast species can lead to the generation of a wide range of metabolites with interesting bioactivities such as organic acids, sugars, phenolic compounds. Kombucha produced from green and black tea contain many phenolic compounds, which contribute to its antioxidant and anti-inflammatory activity and effect on the intestinal microbiota. However, there is a lack of intervention trials investigating the health benefits of fermented foods. Therefore, the investigators propose a human intervention study to assess if daily consumption of two servings of kombucha will alter the intestinal microbiota, decrease inflammation, and improve digestive health in a two-phase design in a free-living population.
This will be a randomized, controlled, two arm intervention study. The study will be conducted in 30 healthy, free-living subjects (21-55 years). After 4-weeks of consuming a beige diet (i.e. low-fiber, low polyphenol diet), 20 subjects will consume one bottle (two servings) of kombucha daily for 4 weeks and 10 subjects will not change their dietary habits. At baseline (week 0), week 4 and 8, blood will be collected. On the day prior to the study visits at week 4 and 8, participants will collect a stool and bring it to the lab. On the day of study visit week 0, 4, and 8, body weight and composition will be determined, and questionnaires and 3-day food record will be collected.
- Conditions
- Health Behavior
- Being tested
- Kombucha beverage
- Keywords
- Microbiome, Inflammation, Biochemical indicators
- Medical subject headings
- Health Behavior, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Kombucha beverageDietary supplement
After 4-weeks of consuming a beige diet (i.e. low-fiber, low polyphenol diet), 20 subjects (kombucha group) will consume one bottle (two servings) of kombucha daily for 4 weeks and 10 subjects (control group) will not change their dietary habits
| Study group | Role | What they receive |
|---|---|---|
| Control group | No intervention | No intervention to be administered |
| Kombucha group | Experimental | Two servings of a 16 oz commercial kombucha beverage daily for four weeks Receives: Dietary Supplement: Kombucha beverage |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in microbiome species richness and abundance of participants at time point 2 (week 8) from baseline (week 0)
Shotgun metagenomic sequencing will be employed on fecal samples collected at three time points in the study period to capture the microbiome profile
Measured: Three time points which are baseline(week 0), time point 1(week 4) and time point 2 (week 8)
Secondary outcomes (8)
Change in fasting blood glucose levels at time point 2 from baseline (week 0)
fasting glucose (mg/dL) will be measured from blood samples during the study
Measured: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood insulin levels at time point 2 (week 8) from baseline (week 0)
Fasting insulin (μU/mL) will be measured from blood samples during the study
Measured: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood triglycerides levels at time point 2 (week 8) from baseline (week 0)
Fasting triglycerides (mg/dL) will be measured from blood samples during the study
Measured: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood cholesterol levels at time point 2 (week 8) from baseline (week 0)
Total cholesterol, High density lipoprotein (HDL) cholesterol and low density lipoprotein (LDL) cholesterol (mg/dL) will be measured from blood samples during the study
Measured: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood glycated hemoglobin (HbA1C) at time point 2 (week 8) from baseline (week 0)
Glycated hemoglobin (hbA1c) (%) will be measured from blood samples during the study
Measured: Baseline (week 0) and time point 2 (week 8)
Change in serum interleukin (IL)10 levels at time point 2 (week 8) from baseline (week 0)
Measurement of serum interleukin (IL) 10 levels (pg/mL) by flow cytometry
Measured: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
Change in serum interleukin (IL) 6 levels at time point 2 (week 8) from baseline (week 0)
Measurement of serum interleukin (IL) 6 levels (pg/mL) by flow cytometry
Measured: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
Change in serum C-reactive protein (CRP) levels at time point 2 (week 8) from baseline (week 0)
Measurement of serum C-reactive protein (CRP) levels by flow cytometry
Measured: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jul 2024
- Study start3 Mar 2022
- Primary completion1 Dec 2022
- Study completion25 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Health BehaviorStudies of the same condition, open and under way.
- More trials run by University of California, San DiegoThe 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Care provider, Investigator
- Enrolment
- 31 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Diego
- Sponsor type
- University, hospital or other
- Collaborators
- GT's Living Foods
- Responsible party
- Principal investigator, Jack Gilbert, University of California, San Diego
- Investigators
- Jack A Gilbert, Ph.D., Principal investigator, UC San Diego
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06484504
- Sponsor's protocol ID
- 210823
- Acronym
- KOMICS
- Status last verified
- Jul 2024
- First submitted
- 7 Jun 2024
- Last updated
- 3 Jul 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Jul 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Kombucha Consumption on the Microbiome in Healthy Subjects
- ClinicalTrials.gov ID
- NCT06484504
- Acronym / sponsor ID
- KOMICS / 210823
- Conditions
- Health Behavior
- Keywords
- Microbiome, Inflammation, Biochemical indicators
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 31 participants (actual)
- Lead sponsor
- University of California, San DiegoUniversity, hospital or other
- Collaborators
- GT's Living Foods
- Study start
- 3 Mar 2022 (actual)
- Primary completion
- 1 Dec 2022 (actual)
- Study completion
- 25 Apr 2024 (actual)
- First posted
- 3 Jul 2024 (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.
This proposed pilot study will assess the ability of consumption of two servings of kombucha daily to decrease inflammation, alter the gut microbiome composition, and improve intestinal wellbeing in a free-living population. The primary objective is to determine changes in the fecal microbiome composition. Secondary outcomes will be bacterial metabolites (fecal indole propionic acid, calprotectin), serum interleukin (IL) 6, interleukin (IL) 10, C-reactive protein (CRP), C-peptide, insulin, fasting glucose, Homeostatic Model Assessment for Insulin Resistance (HOMA), 14-day continuous glucose monitor, digestive health, dietary information, general Health \& Wellness at 4 and 8 weeks.
Detailed description
An altered intestinal gut microbiota, i.e. dysbiosis, has been associated with the development of intestinal disease including inflammatory bowel disease and metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disease. Fermented foods such as Kefir, Kombucha, Miso, and Kimchi contain potentially probiotic microorganisms. The characteristic microbiome in kombucha includes several genera of acetic acid bacteria, yeasts and lactic acid bacteria. Interactions between bacteria and yeast species can lead to the generation of a wide range of metabolites with interesting bioactivities such as organic acids, sugars, phenolic compounds. Kombucha produced from green and black tea contain many phenolic compounds, which contribute to its antioxidant and anti-inflammatory activity and effect on the intestinal microbiota. However, there is a lack of intervention trials investigating the health benefits of fermented foods. Therefore, the investigators propose a human intervention study to assess if daily consumption of two servings of kombucha will alter the intestinal microbiota, decrease inflammation, and improve digestive health in a two-phase design in a free-living population.
This will be a randomized, controlled, two arm intervention study. The study will be conducted in 30 healthy, free-living subjects (21-55 years). After 4-weeks of consuming a beige diet (i.e. low-fiber, low polyphenol diet), 20 subjects will consume one bottle (two servings) of kombucha daily for 4 weeks and 10 subjects will not change their dietary habits. At baseline (week 0), week 4 and 8, blood will be collected. On the day prior to the study visits at week 4 and 8, participants will collect a stool and bring it to the lab. On the day of study visit week 0, 4, and 8, body weight and composition will be determined, and questionnaires and 3-day food record will be collected.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control group | No intervention | –No intervention to be administered |
| Kombucha group | Experimental | Dietary Supplement: Kombucha beverageTwo servings of a 16 oz commercial kombucha beverage daily for four weeks |
Who may qualify
- Ages
- 21 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Typically consume low fiber/polyphenol diet (beige diet)
- BMI within 25-29.9 kg/m2
Key exclusion criteria (7 listed)
- Eating a high fiber/polyphenol diet or taking any medication or dietary supplement, which interfere with the absorption of polyphenols
- History of gastrointestinal surgery, diabetes mellitus on medications, or other serious medical condition, such as chronic hepatic or renal disease, bleeding disorder, congestive heart disease, chronic diarrhea disorders, myocardial infarction, coronary artery bypass graft, angioplasty within 6 months prior to screening, current diagnosis of uncontrolled hypertension (defined as systolic BP >160mmHg, diastolic BP > 95mmHg), active or chronic gastrointestinal disorders, bulimia, anorexia, laxative abuse, or endocrine diseases (except thyroid disease requiring medication) as indicated by medical history or routine physical examination
- Is unable or unwilling to comply with the study protocol
- Using prebiotics, probiotics, yogurt, and/or any fiber supplements regularly
- Taking antibiotics or laxatives within the past 3 months
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 |
|---|---|---|
| Kombucha beverageAfter 4-weeks of consuming a beige diet (i.e. low-fiber, low polyphenol diet), 20 subjects (kombucha group) will consume one bottle (two servings) of kombucha daily for 4 weeks and 10 subjects (control group) will not change their dietary habits | Dietary supplement | Kombucha group |
Primary outcome
Change in microbiome species richness and abundance of participants at time point 2 (week 8) from baseline (week 0)
Time frame: Three time points which are baseline(week 0), time point 1(week 4) and time point 2 (week 8)
Shotgun metagenomic sequencing will be employed on fecal samples collected at three time points in the study period to capture the microbiome profile
8 secondary outcomes
Change in fasting blood glucose levels at time point 2 from baseline (week 0)
Time frame: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood insulin levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood triglycerides levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood cholesterol levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0) and time point 2 (week 8)
Change in fasting blood glycated hemoglobin (HbA1C) at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0) and time point 2 (week 8)
Change in serum interleukin (IL)10 levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
Change in serum interleukin (IL) 6 levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
Change in serum C-reactive protein (CRP) levels at time point 2 (week 8) from baseline (week 0)
Time frame: Baseline (week 0), time point 1 (week 4) and time point 2 (week 8)
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 3 Jul 2024.
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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.
Jack A Gilbert, Ph.D. principal investigator
UC San Diego
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Kombucha beverage in people with Health Behavior, run by University of California, San Diego 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 2 inclusion and 7 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 3 Jul 2024. 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 microbiome species richness and abundance of participants at time point 2 (week 8) from baseline (week 0) (time frame: Three time points which are baseline(week 0), time point 1(week 4) and time point 2 (week 8)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 3 Jul 2024.