The Role of Gut Microbiota in Hypertension

August 12, 2025 updated by: University of Florida

The Role of Gut Microbiota in Hypertension: Brain-Gut Microbiome-Immune Axis in Hypertension

Hypertension is the single most prevalent risk factor for heart diseases, heart failure, kidney failure and stroke. About 1 in 3 adults in the United States have hypertension. Approximately 28-30% of hypertensive patients suffer from resistant hypertension (RH). Inflammation has been implicated in the pathogenesis of the hypertension. Additional data suggests the involvement of gut microbiota in host normal cardiovascular functions and pathophysiology. Accumulating evidence demonstrates that antibiotic treatment benefits patients with acute coronary syndromes and reduces the incidence of ischemic cardiovascular events. Even though these studies did not address effects of antibiotic treatment on the gut microbiota, it is possible that gut microbiota could affect neurologic inflammation. Finally, intestinal microbiota has recently been proposed to modulate blood pressure (BP) through production of short-chain fatty acids. In order to investigate this, the investigators hypothesize that gut microbiota is involved in the neuroinflammation-mediated initiation and establishment of RH, and targeting gut microbiota by minocycline would produce beneficial outcomes in RH.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a prospective cohort design. This study will enroll 388 subjects: 81 patients without HTN as a reference group, 81 patients with controlled HTN, 55 patients with uncontrolled HTN, 55 with remodeled RH, and 81 patients with RH to characterize gut microbiota composition. Subjects will provide stool samples for analysis. Subjects will also provide a blood sample for inflammatory marker and stem cell analysis.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
292

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Eileen M Handberg, PhD
  • Phone Number: 352-273-8944
  • Email: handbem@ufl.edu

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32610
        • Cardiovascular Clinic at UF Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

This study will initially enroll 10 patients without hypertension as normal controls, and 10 patients with controlled hypertension and 10 patients with resistant hypertension to characterize gut microbiota. In addition, all patients enrolled in IRB# 102-2013 will be approached for possible participation.

Description

Inclusion Criteria:

  • age >18 and <80
  • is competent and willing to provide consent

Inclusion criteria for each subject group:

  • Control subjects will have a systolic BP <140mmHg with no cardiovascular disease
  • Patients with controlled hypertension
  • Patients with uncontrolled hypertension
  • Resistant hypertension subjects will have systolic blood pressure (BP) ≥140 mmHg despite ≥3 anti-hypertensive medications of different classes one of which should be a diuretic
  • Patients who are no longer RH subjects and have normal blood pressure
  • Subjects participating in NCT 02133872 will be eligible to participate

Exclusion Criteria:

  • currently pregnant or have been pregnant in the last 6 months;
  • antibiotic treatment within 2 months of study enrollment;
  • currently taking a medication (e.g., antibiotic, anti-inflammatory agents, glucocorticoids or other immune modulating medications);
  • unwilling to discontinue vitamin or supplements, including probiotics, potentially affecting gut microbiota (vitamins/supplements and medications that possibly affect the gut microbiota should be discontinued for at least 2wks prior to stool collection);
  • history of intestinal surgery, inflammatory bowel disease, celiac disease, lactose intolerance, chronic pancreatitis or other malabsorption disorder.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Normal controls without hypertension
Control subjects will have a systolic BP <140mmHg with no cardiovascular disease. These subjects will provide a one time stool sample and a blood sample.
Other: Stool Sample and Blood Sample
All subjects will provide a stool sample and a blood sample at baseline. Subjects in NCT02133872 will provide a second stool sample and blood sample at their 3 month visit.
Controlled hypertension
Subjects with controlled hypertension will provide a one time stool sample and a blood sample.
Other: Stool Sample and Blood Sample
All subjects will provide a stool sample and a blood sample at baseline. Subjects in NCT02133872 will provide a second stool sample and blood sample at their 3 month visit.
Resistant hypertension
Resistant hypertension subjects will have systolic blood pressure (BP) ≥140 mmHg despite ≥3 anti-hypertensive medications of different classes. These subjects will provide a one time stool sample and a blood sample.
Other: Stool Sample and Blood Sample
All subjects will provide a stool sample and a blood sample at baseline. Subjects in NCT02133872 will provide a second stool sample and blood sample at their 3 month visit.
Prior enrolled in NCT 02133872
These subject will be asked to provide two stool samples and two blood samples. One at baseline and one after 3 months of therapy.
Other: Stool Sample and Blood Sample
All subjects will provide a stool sample and a blood sample at baseline. Subjects in NCT02133872 will provide a second stool sample and blood sample at their 3 month visit.
Remodeled Resistent Hypertension
Subjects with controlled hypertension will provide a one time stool sample and a blood sample.
Other: Stool Sample and Blood Sample
All subjects will provide a stool sample and a blood sample at baseline. Subjects in NCT02133872 will provide a second stool sample and blood sample at their 3 month visit.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Characterize gut microbiota composition at phylum level
Time Frame: 24 hours
Stool samples to analyze the composition of the microbiota, extracted bacterial genomic DNA will be used as a template for PCR reactions targeting the V4-V5 variable regions of the 16S rRNA gene. Amplicons generated from the PCR will be run on the Illumina MiSeq sequencing platform available in our laboratory to profile microbial communities at phylum level.
24 hours
Characterize gut microbiota composition at genus level
Time Frame: 24 hours
Stool samples to analyze the composition of the microbiota, extracted bacterial genomic DNA will be used as a template for PCR reactions targeting the V4-V5 variable regions of the 16S rRNA gene. Amplicons generated from the PCR will be run on the Illumina MiSeq sequencing platform available in our laboratory to profile microbial communities at genus level.
24 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Reduction in BP is associated with changes in gut microbiota composition in RH subjects.
Time Frame: Baseline, 3 months
Stool samples from patients enrolled in NCT 02133871 that received minocycline medication for resistant hypertension. Will be used to analyze the composition of the microbiota and data (taxonomic assignment) will be analyzed using QIIMEv1.3 pipeline to enumerate microbial population between samples derived from the cohorts.
Baseline, 3 months
IS hypertension associated with increased sympathetic activity and decreased parasympathetic activity and whether minocycline or other tetracyclines are effective to improve this balance
Time Frame: Baseline and 3 months
Stool samples from patients enrolled in NCT 02133871 that received minocycline
Baseline and 3 months
To determine if characterization of gut microbiota in at risk patients predicts long term care utilization and/or cardiovascular outcomes
Time Frame: Up to 5 years
Stool samples
Up to 5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Florida

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Heart, Lung, and Blood Institute (NHLBI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Carl Pepline, MD, University of Florida

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 9, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 9, 2014

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 11, 2014

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 17, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 12, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB201400233-N
  • 1R01HL132448-01 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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