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The Effect of the Fermented Tea Beverage Kombucha on the Oral and Gut Microflora

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ClinicalTrials.gov Identifier: NCT03873350
Recruitment Status : Completed
First Posted : March 13, 2019
Last Update Posted : March 13, 2019
Sponsor:
Information provided by (Responsible Party):
Åsa Håkansson, Lund University

Brief Summary:
The purpose of the project is to investigate if consumption of the fermented tea beverage kombucha has an effect on the gut and/or oral microbiota, and further if it depends on the content of living bacteria or is inherent even to sterilized kombucha. This will be studied by a clinical trial in which healthy individuals will be given living kombucha, sterilized kombucha or water. The participants will consume one bottle (33 cl) of their designated drink per day for 21 days. Fecal and saliva samples will be collected before, directly and ten days after the intervention. These will then be examined to see if there is a change in the micro flora due to the kombucha.

Condition or disease Intervention/treatment Phase
Microbial Colonization Other: Consumption of kombucha Other: Consumption of heat-sterilized kombucha Not Applicable

Detailed Description:

The first part of the project focuses on studying the characteristics of the kombucha drink and microbial composition. The amount of living organisms in the drink will be determined by colony count. Apart from this, the culture will be studied to determine which organisms are present and which are dominant. After isolation of colonies found from culturing, Sanger sequencing will be used for characterization.

The second part, which consists of the human study, will be performed over a span of 3 weeks and the aim is that 60 persons take part. The participants should be healthy, and have no diagnosed gut or stomach problems, and be 18 years old or older. They will be divided into groups, where one will be given living kombucha, one group kombucha sterilized by boiling (placebo) and the final group plain water (control group). The participants will drink one bottle (33 cl) of their designated beverage daily for two weeks. Fecal and saliva samples will be collected before, directly after and 10 days after the intervention. The samples will then be studied by sequencing the present organisms, after having extracted them. The library preparation will be made using Illumina sequencing. If possible, the aim is also to re-isolate a species from the kombucha after the study.

The participants will be registered for the study as they sign a consent form. These forms will then be treated as confidential material, and therefore be kept locked away at the institution. Only participating researchers will have access to the forms.

The participants will store the samples collected during the study until they are handed in for analysis. The samples will be destroyed during analysis.

The sample size has been chosen to a maximum of 60 participants, due to economical boundaries, but mainly because similar studied have used even fewer participants. As this is a pilot study more is not necessary. The intervention time (three weeks) was determined by comparison to other studies, but also restricted by the time scope of the project.


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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 42 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: The participants will be divided into three groups in which one is given living kombucha, one heat-sterilized kombucha (placebo group) and one regular tap water (control group).
Masking: Double (Participant, Investigator)
Masking Description: The participants will be masked, meaning they will not know if they are given living or sterilized kombucha. The control group consuming water will know that they are the control group.
Primary Purpose: Other
Official Title: The Effect of the Fermented Tea Beverage Kombucha on the Human Microflora: a Placebo-controlled Study
Actual Study Start Date : April 1, 2018
Actual Primary Completion Date : May 2, 2018
Actual Study Completion Date : May 4, 2018

Arm Intervention/treatment
Experimental: Living kombucha Other: Consumption of kombucha
The intervention performed in the study implies letting healthy individuals consume one bottle (33 cl) of living kombucha daily for three weeks.

Placebo Comparator: Heat-sterilized kombucha Other: Consumption of heat-sterilized kombucha
The intervention performed in the study implies letting healthy individuals consume one bottle (33 cl) of heat-sterilized kombucha daily for three weeks.

No Intervention: Water



Primary Outcome Measures :
  1. The primary outcome is a change in the composition of the gut of oral micro flora, measured by extraction and sequencing of genetic material in fecal and saliva samples. [ Time Frame: Samples will be collected before, directly after and ten days after the end of the intervention. ]
    A library will be created using Illumina sequencing that will enable comparing the microbiological composition before and after the intervention.


Secondary Outcome Measures :
  1. The secondary outcome of the study is to be able to re-isolate a species from the kombucha in the collected samples after the intervention. [ Time Frame: Samples will be collected before, directly after and ten days after the intervention. The kombucha culture is studied before the intervention. ]
    The secondary outcome will be measured by comparing results from the sequencing of microbes in the collected human samples and from the kombucha drink itself.



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • The participants should be above 18 years of age.
  • The participants must live in proximity of Lund or Helsingborg to be able to leave samples collected.
  • The participants should consider themselves healthy and have no gut or stomach problems.

Exclusion Criteria:

  • The participants should not be diagnosed with any gut or stomach diseases or problems.
  • The participants cannot consume any food with living microorganisms two weeks before, during of ten days after the intervention.
  • Participants cannot use anti-microbial oral products during the study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03873350


Locations
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Sweden
Lund University
Lund, Skåne, Sweden, 22100
Sponsors and Collaborators
Lund University

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Responsible Party: Åsa Håkansson, Assistant university lecturer at the Department of Food Technology, Lund University, Lund University
ClinicalTrials.gov Identifier: NCT03873350     History of Changes
Other Study ID Numbers: Kombucha study 2018
First Posted: March 13, 2019    Key Record Dates
Last Update Posted: March 13, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: No plan to share participant data.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Åsa Håkansson, Lund University:
Microbiota colonization kombucha bacteria yeast
Additional relevant MeSH terms:
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Communicable Diseases
Infection