Kombucha in Overweight and Obese: Live Vs. Pasteurized Effects on Microbiota, Metabolism, and Liver Function

NCT06759324 | Recruiting

• 2 other identifiers: FUSILLI: PARECER (02/2024)Grant agreement No. 101000717
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 2

Brief Summary

Kombucha, a fermented beverage made from Camellia sinensis tea (black, oolong, or green) with sugar and a symbiotic culture of bacteria and yeast (SCOBY), has gained global attention for its potential health benefits. Factors like the type and amount of sugar substrate, fermentation time, and temperature significantly influence its organic compounds, total phenolics, vitamin content, and alcohol levels. In a previous study, kombucha's impact on glucose tolerance, insulin sensitivity, body composition, and liver function was tested in male prediabetic mice with diet-induced obesity. Daily supplementation (200 µL per mouse) improved glucose tolerance after nine days (equivalent to one year in humans) and reduced liver steatosis, despite no changes in body composition. Although kombucha has been associated with antioxidant, antimicrobial, probiotic, antidiabetic, and anticancer activities, strong scientific evidence in humans remains limited. Further clinical studies are needed to substantiate kombucha's health benefits in humans.

Conditions

Obesity and Overweight

Keywords

kombucha; gut microbiota; obesity; liver function; fermented beverages; Randomized Controlled Trial; overweight; fermented tea; SCOBY; live vs pasteurized kombucha; Small Intestinal Bacterial Overgrowth (SIBO); Bristol Stool Form Scale; Likert Scale Analysis; Nutritional Interventions; Inflammatory Biomarkers; metabolic parameters

Outcome Measures

Primary Outcomes (5)

• Change in Gut microbiota composition and diversity (fecal samples)

  Analyze the changes in the relative abundance of the microbial species present, including taxonomic identification and diversity analysis, from baseline to the end of intervention, by next-generation sequencing (NGS).

  4 weeks

• Change in fasting glucose levels

  Fasting glucose (mg/dl), from baseline to the end of intervention. Reduction is a better outcome.

  4 weeks

• Change in fasting insulin levels

  Fasting insulin (μUI/mL), from baseline to the end of intervention. Reduction is a better outcome.

  4 weeks

• Changes in Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) values

  HOMA-IR values, from baseline to the end of intervention. Calculated from fasting glucose (mmol/L) X fasting insulin (mU/L) / 22.5). Less than 1.0 means insulin-sensitive, which is optimal. Above 1.9 indicates early insulin resistance. Above 2.9 indicates significant insulin resistance. Reduction is a better outcome.

  4 weeks

• Changes in Lipid profile

  Lipid profile (total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides), in mg/dL, from baseline to the end of intervention.

  4 weeks

Secondary Outcomes (9)

• Stool consistency rating by Bristol Stool Scale

  4 weeks

• Variation in SIBO diagnosis (positive/negative) measured by methane and hydrogen levels in breath test

  4 weeks

• Change in liver enzyme levels

  4 weeks

• Change in levels of oxidative stress biomarker (ratio 8-iso-PGF2α to prostaglandin F2α (PGF2α))

  4 weeks

• Change in gastrointestinal symptoms using a Likert scale

  4 weeks

Other Outcomes (5)

• Body weight change

  4 weeks

• BMI change

  4 weeks

• Waist circumference change

  4 weeks

Study Arms (3)

Intervention: Kombucha (live drink)

EXPERIMENTAL

The first arm receives a daily amount of 33 cl of kombucha (live drink) for 4 weeks (dietary supplement).

Dietary Supplement: Live kombucha (non filtered/ non pasteurized)

Intervention: Pasteurized kombucha

EXPERIMENTAL

The second arm receives a daily amount of 33 cl of kombucha (pasteurized drink) for 4 weeks (dietary supplement).

Dietary Supplement: Pasteurized kombucha (non filtered)

Sparkling water

ACTIVE COMPARATOR

The third arm receives 33 cl of sparkling water for 4 weeks (control).

Other: Control (sparkling water)

Interventions

Live kombucha (non filtered/ non pasteurized) DIETARY_SUPPLEMENT

Participants receive a daily amount of 33 cl of live kombucha (non-pasteurized/ non-filtered) for 4 weeks (28 days).

Intervention: Kombucha (live drink)

Pasteurized kombucha (non filtered) DIETARY_SUPPLEMENT

Participants receive a daily amount of 33 cl of kombucha (pasteurized drink) for 4 weeks (28 days).

Intervention: Pasteurized kombucha

Control (sparkling water) OTHER

Participants receive a daily amount of 33 cl of sparkling water for 4 weeks.

Sparkling water

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Individuals with a Body Mass Index (BMI) between 25 kg/m² and 34.9 kg/m², of both biological sexes, aged between 18 and 60 years, available to comply with the study protocol (described in this document) and sign informed consent.

You may not qualify if:

• Volunteers will be excluded from the study if they present one or more of the following conditions:
• Subjects with sensitivity to kombucha;
• Consumption of kombucha, kefir, kimchi, cheese, raw vinegar, sauerkraut, kvass, and other fermented products during the study and in the 3 weeks before the study.
• Use of antibiotics in the 6 months prior to the start of the study;
• Use of pro/prebiotics or fibers as dietary supplements or any food/molecule that modifies intestinal transit time 6 weeks before recruitment; use of laxatives 6 weeks before recruitment;
• Specific dietary regimen (e.g., vegan); specific dietary treatment (e.g., high protein);
• Excessive consumption of substances and alcohol; smokers;
• Diagnosis of gastrointestinal disorders, hormonal or thyroid diseases, autoimmune diseases, and/or chronic use of corticosteroids; psychiatric disease; Type 1 or 2 diabetes;
• Use of proton pump inhibitors; antidiabetic drugs or insulin and statins;
• Subjects with insulin sensitivity;
• Pregnant or lactating women;
• Subjects with tooth sensitivity
• Participation in another clinical trial in the last 3 months.

Sponsors & Collaborators

• Associação Centro de Apoio Tecnológico Agro Alimentar: lead

Study Sites (2)

Centro de Apoio Tecnológico Agro Alimentar (CATAA)

Castelo Branco, Castelo Branco District, 6000-459, Portugal

RECRUITING

Centro de Apoio Tecnológico Agro Alimentar (CATAA) (facilities temporarily provided by the Affidea clinical analysis center)

Covilha, 6200-077, Portugal

RECRUITING

Related Publications (1)

• Moreira GV, Araujo LCC, Murata GM, Matos SL, Carvalho CRO. Kombucha tea improves glucose tolerance and reduces hepatic steatosis in obese mice. Biomed Pharmacother. 2022 Nov;155:113660. doi: 10.1016/j.biopha.2022.113660. Epub 2022 Sep 12.

  PMID: 36095960 BACKGROUND

MeSH Terms

Conditions

Obesity; Overweight

Interventions

Carbonated Water

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Mineral Waters; Water; Hydroxides; Alkalies; Inorganic Chemicals; Anions; Ions; Electrolytes; Oxides; Oxygen Compounds; Carbonated Beverages; Beverages; Diet, Food, and Nutrition; Physiological Phenomena; Drinking Water; Food and Beverages

Study Officials

• Brandão, PhD

  CATAA

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Inês Brandão, PhD

CONTACT

+351926777221; inesbrandao@cataa.pt

Filomena Pereira, Nutritionist

CONTACT

filomenapereira@cataa.pt

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Partial double blinding (participants will not know if they are consuming live or pasteurized kombucha; the nutritionist will not know which arm the participant belongs to; the technician responsible for microbiota sequencing will receive coded samples without information regarding the intervention/control arm the sample belongs to).
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: The study aims to recruit at least 30 individuals with overweight and class 1 obesity, aged between 18 and 60 years, randomly distributed into 3 arms (each arm should have about 10 participants). The first arm receives a daily amount of 33 cl of kombucha (live drink) for 4 weeks, the second arm receives a daily amount of 33 cl of kombucha (pasteurized drink) for 4 weeks. The control group receives 33 cl of water for 4 weeks. Kombucha samples are prepared for the study by Erfrischerling GmbH \& Co. KG (Germany).

Study Record Dates

• First Submitted: December 9, 2024
• First Posted: January 6, 2025
• Study Start: October 11, 2024
• Primary Completion: February 28, 2025
• Study Completion: February 28, 2025
• Last Updated: January 6, 2025

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will not share

Locations

PT (2)