Effects of Cannabidiol and Tetrahydrocannabinol on Microbiome and Neuroinflammation in HIV (CAMI)

April 27, 2026 updated by: Ronald Ellis, University of California, San Diego

Effects of Cannabidiol and Tetrahydrocannabinol on the Microbiome, Endocannabinoids, and Neuroinflammation in HIV

This study has the potential to contribute to a more complete understanding of the independent and combined effects of cannabis use and HIV on the brain and on inflammation. Such knowledge may inform future strategies for treating brain disease and inflammation. Participants will be randomly assigned to one of two groups, both of which will receive the same treatment in a different order over a period of about 6 weeks. The visits include physical examinations, blood tests, and other procedures designed to monitor subject safety and measure the effects of the study drug.

Study Overview

Status

Status

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

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 project will characterize the microbiome and endocannabinoid system (ECS) in people with HIV (PWH) and how they relate to neuroinflammation and blood-brain barrier (BBB) function. The study hypothesizes that pathogenic alterations in the gut microbiota (dysbiosis) and impaired gut barrier integrity (leaky gut) are mediators between the ECS, neuroinflammation and BBB dysfunction in HIV. The major goals are to (1) characterize the gut microbiota and ECS in response to exogenous cannabinoid exposure in both PWH and people without HIV (PWoH); (2) characterize patterns of HIV-associated inflammation (innate, adaptive, T-cell, B-cell) in blood and cerebrospinal fluid (CSF) in response to controlled cannabis exposure; (3) assess effects of cannabinoid exposure on these patterns and how they are mediated through changes in the ECS, gut microbiota and gut barrier function. The investigators will perform a clinical trial of 50 PWH and 50 PWoH exposed in a randomized, cross-over fashion to 14 days each of oral THC and CBD to determine if treatment with either phytocannabinoid reduces inflammation and improves gut function. The experimental approach will use fecal shotgun metagenomic sequencing to characterize the gut microbiome, with particular attention to aerotolerant bacteria, pro-inflammatory species, Prevotella spp., Bifidobacterium and Bacteroides spp. and butyrate-producing bacteria. We will evaluate how the microbiota and leaky gut relate to neuroinflammation and impaired BBB function, the latter potentially leading to increased central nervous system (CNS) exposure to microbially-produced pro-inflammatory ligands. The rationale for the study is that virologic suppression on antiretroviral therapy (ART) does not normalize gut lymphoid tissue cluster of differentiation 4 (CD4)+ T cell depletion, leaky gut, dysbiosis, chronic gut inflammation, and microbial antigen translocation (MAT). These alterations ultimately drive systemic and CNS inflammation. Compromised gut barrier function due to altered tight junctions, apoptosis and reduced epithelial cell proliferation and repair render PWH susceptible to increased tissue exposure to pro-inflammatory ligands produced by gut microbiota and are important in HIV neuropathogenesis. Of particular relevance here are recent findings that the ECS in the large intestine interacts with the gut microbiota to regulate epithelial barrier permeability. Thus, constituents of cannabis, acting through the EC systems in the gut, brain and immune system, may be therapeutic. The existing literature suggests that the two principal constituents of cannabis, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), have differential effects on the ECS.

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.
Interventional

Enrollment (Estimated)

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.
90

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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.

Study Locations

  • United States
    • California
      • San Diego, California, United States, 92103
        • Recruiting
        • HIV Neurobehavioral Research Program (HNRP)
        • Principal Investigator:
          • Ronald J Ellis, MD, PhD
        • Contact:

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

21 years to 60 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

  1. Aged 21 to 70 years old
  2. Possess the capacity to provide informed consent to a set of neuromedical assessment procedures.
  3. Experience with cannabis use at least once in the past 5 years without major adverse effects (e.g., psychosis, syncope)
  4. No or low cannabis use in the past 2 weeks, defined as no cannabis exposure or use or use limited to only once in the past 2 weeks.
  5. Willing to abstain from use of cannabis, CBD, THC, or synthetic cannabinoids outside the study during the 6-week intervention

  6. Individuals with HIV must meet the following criteria

    1. Virally suppressed on stable ART for at least 6 months and have no more than 1 prior event of virologic failure (i.e., required change in ARTs due to virologic failure)
    2. Stage 1 or 2 infection
    3. Have a "normal" CD4 count defined as ≥350 cells/microliter
    4. No significant history of ART regimen adherence challenges
  7. Ability to adhere to the study visit schedule.

Exclusion Criteria:

  1. Exclusion criteria will be: any substance use disorder (abuse or dependence) other than cannabis in the last 30 days;
  2. Significant cognitive impairment such as Dementia, including Alzheimer's disease
  3. Pregnancy or lactation, or unwillingness to prevent pregnancy during the trial; refusal to maintain highly effective contraceptive methods (e.g., implants, injectables, combined oral contraceptives, some intrauterine devices (IUDs), sexual abstinence or vasectomized partner) during the study for persons of child-bearing potential or those with partners of child-bearing potential
  4. Evidence of moderately or worse compromised liver or kidney function, including moderate (Child-Hugh B) or severe (Child-Hugh C) hepatic impairment and AST and ALT above ULN and total bilirubin above ULN;
  5. Evidence of significant cardiovascular risk, resting heart rate <50 or >110 beats per minute, uncontrolled hypertension (systolic blood pressure <80 or >140 mmHg; diastolic blood pressure <50 or >90 mmHg), history of myocardial infarction, congestive heart failure, or arrhythmia);
  6. Evidence of chronic pulmonary disease requiring supplemental oxygen;
  7. Active, recent, or remote medical history of hepatobiliary-related illness, including elevated transaminase levels above 3 times the upper limit of normal accompanied by elevations in total bilirubin above 2 times the upper limit of normal at screening;
  8. Insulin dependent diabetics
  9. Allergy to the study drugs or any of their constituents including sesame
  10. Use of medications with absolute contraindicated or potential significant interactions
  11. Use of sedating medications
  12. Weighing less than 60 kg at screening to minimize the risk of elevated transaminases as a result of exposure to cannabidiol;
  13. Active, uncontrolled psychiatric disorder with psychotic features, severe depression, or suicidality; Participants will be excluded if they have had a history of suicide attempt, recent suicidal ideation or behavior as indexed by their Beck Depression Inventory-II (BDI-II) score is greater than or equal to 29 (severe depression).
  14. Neurologic disorder that could compromise interpretation of study findings, including uncontrolled seizure disorder (active seizures within the past 3 months), multiple sclerosis, Parkinson's disease, Alzheimer's disease, and recent (past 3 months) cerebral infarction or hemorrhage with neurological sequelae.

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
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.
Experimental: THC first, then CBD
THC 10mg daily for 2 weeks, followed by washout for 2 weeks, followed by CBD 600mg daily for 2 weeks
Drug: THC
THC capsule
Other Names:
  • Tetrahydrocannabinol
  • Delta-9 tetrahydrocannabinol
  • Delta9-THC
Drug: CBD
oral solution
Other Names:
  • Cannabidiol
Active Comparator: CBD first, then THC
CBD 600mg daily for 2 weeks, followed by washout for 2 weeks, followed by THC 10mg daily for 2 weeks
Drug: THC
THC capsule
Other Names:
  • Tetrahydrocannabinol
  • Delta-9 tetrahydrocannabinol
  • Delta9-THC
Drug: CBD
oral solution
Other Names:
  • Cannabidiol

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
PC1
Time Frame: Change from baseline to Week 2
A composite marker of inflammation, comprising the first component (PC1, a unitless measure) of the principal component analysis (PCA) of 7 soluble biomarkers in blood (soluble CD163 [sCD163], interferon gamma [IFN-gamma], interleukin 6 [IL-6], C-reactive protein [CRP], CC motif chemokine ligand 2 [CCL2], neopterin and soluble tumor necrosis factor - type II [sTNFRII]), all measured in picograms/milliliter
Change from baseline to Week 2
PC1
Time Frame: Change from Week 4 to Week 6
A composite marker of inflammation, comprising the first component (PC1, a unitless measure) of the principal component analysis (PCA) of 7 soluble biomarkers in blood (soluble CD163 [sCD163], interferon gamma [IFN-gamma], interleukin 6 [IL-6], C-reactive protein [CRP], CC motif chemokine ligand 2 [CCL2], neopterin and soluble tumor necrosis factor - type II [sTNFRII]), measured in picograms/milliliter
Change from Week 4 to Week 6

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
blood-brain barrier (BBB)
Time Frame: Change from baseline to Week 2
BBB markers: claudin, suPAR, CSF/serum albumin ratio, MMP-2, occludin, all measured in picograms/milliliter
Change from baseline to Week 2
blood-brain barrier (BBB)
Time Frame: Change from Week 4 to Week 6
BBB markers: claudin, suPAR, CSF/serum albumin ratio, MMP-2, occludin, measured in picograms/milliliter
Change from Week 4 to Week 6

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 California, San Diego

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: Ronald J Ellis, MD, PhD, UC San Diego

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.
September 1, 2023

Primary Completion (Estimated)

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.
October 31, 2027

Study Completion (Estimated)

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.
October 31, 2027

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).
August 22, 2022

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.
August 22, 2022

First Posted (Actual)

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.
August 25, 2022

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.
May 1, 2026

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.
April 27, 2026

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.
April 1, 2026

More Information

Terms related to this study

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.
  • 802514 (U Penn IRB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Data sharing will be considered upon request

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings