COVID-19NCT06825819
Dysbiosis & Long COVID
An observational study of COVID-19, run by University of Chicago at 1 site in United States.
Trial summary
The SARS-CoV-2 virus causes COVID-19, which ranges from mild initial symptoms to severe multi-organ dysfunction. While some patients recover to their baseline states, others develop a long COVID, or post-acute sequelae of SARS-CoV-2 (PASC) consisting of symptoms persisting >2-6 months post-infection. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- COVID-19
- What is being tested?
- Subjects with and without Long COVID
- How many people
- 400 participants
- Where
- 1 siteUnited States
- Study dates
- 21 Jan 2025to Jan 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: We will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community with and without long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. We will recruit a total of 400 subjects (200 ea. w/ and w/o long COVID). The research will be conducted at UCM clinic sites and in laboratory facilities
Who may be able to join
- Age: 18-80
- Sex: Any
- Race: Any
- Last COVID infection: within past 3 years, PCR- or antigen-confirmed, symptomatic (mild/moderate/severe)
- COVID vaccination status: Any
- Presence of long COVID symptoms (GI, cardiac, pulmonary, neuro, musculoskeletal, and/or psych): 200 with symptoms, 200 w/o symptoms as defined by SBQ-LCTM.
- May or may not be doing routine endoscopy at UCM
Who cannot join
- Age <18 or >80
- Last COVID infection >3 years ago (PCR/antigen-confirmed, symptomatic)
- Currently or within the last 3 months COVID+ by nasopharyngeal PCR/antigen test
- Currently diagnosed with cancer
- Currently pregnant (cannot take colon biopsy sample; only eligible for survey/blood \& stool collection)
- Currently on biologic immunomodulatory medications
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- Official diagnosis of irritable bowel disease (IBD) or other chronic GI disorder
- Vulnerable and/or Special Populations
- Healthy adult volunteers
- Pregnant people
- UCMC and UChicago employees
- Staff/faculty
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
The University of Chicago
Chicago, Illinois, 60637
Lavanya Visvabharathy, Ph.D, 773-834-5087
Leila Yazdanbakhsh, MSCI, 7738345087, leila.yazdanbakhsh@bsd.uchicago.edu
About this study
Official title: DETERMINING THE IMPACT OF MICROBIAL DYSBIOSIS ON IMMUNE AND BARRIER DYSFUNCTION IN LONG COVID
The SARS-CoV-2 virus causes COVID-19, which ranges from mild initial symptoms to severe multi-organ dysfunction. While some patients recover to their baseline states, others develop a long COVID, or post-acute sequelae of SARS-CoV-2 (PASC) consisting of symptoms persisting >2-6 months post-infection. PASC symptoms include post-exertional malaise, fatigue, and heart palpitations as well as incident GI disorders, cognitive dysfunction, and arthritis. Based on prevalence/incidence studies, it is estimated that more than 30 million people in the US have ever developed PASC with 10-11% of patients or 11 million people continuing to feel symptoms to the present day10. SARS-CoV-2 vaccines are only ~32% effective against infection at 4 months post-vaccination11, only 15% effective against the development of PASC12, and only 20% of American adults have received an updated booster as of December 202313. It is therefore imperative that the scientific community make progress in identifying underlying causes of PASC to develop effective treatments.
This study will identify microbial metabolites associated with PASC-mediated gut dysbiosis and establish a tractable in vitro model to test T cell-gut epithelium dynamics to develop novel bio-therapeutics for multiple post-viral conditions. This case-control study will collect biospecimens (matched stool \& blood) samples from 400 people with and without long COVID (200 participants/group) to understand how COVID-induced dysbiosis impacts symptom severity, immune suppression, and gut barrier dysfunction both ex vivo and in vitro.
- Conditions
- COVID-19
- Being tested
- Subjects with and without Long COVID
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Subjects with and without Long COVIDBiological
To collect biospecimens (matched stool \& blood) samples from 400 people with and without long COVID (200 participants/group) to understand how COVID-induced dysbiosis impacts symptom severity, immune suppression, and gut barrier dysfunction both ex vivo and in vitro.
| Study group | Role | What they receive |
|---|---|---|
| Subjects without Long COVID symptoms | We will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community without long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. Receives: Biological: Subjects with and without Long COVID | |
| Subjects with Long COVID symptoms | We will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community with long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. Receives: Biological: Subjects with and without Long COVID |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine whether people with long COVID exhibit microbial dysbiosis characterized by decreased bacterial diversity, overgrowth of Bacteroides taxa, and lower SCFA, indole, and secondary bile acid production with biospecimen collections
Measured: At baseline until final values
Secondary outcomes (1)
To collect matched stool, blood, and intestinal biopsy samples from a cohort of 300 individuals with and without long COVID (150/group)
Measured: At baseline until final values
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Feb 2025
- Study start21 Jan 2025
- Primary completionJan 2029 (estimated)
- Study completionJan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by University of ChicagoThe 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Chicago
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Lavanya Visvabharathy, Ph.D, Principal investigator, University of Chicago
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06825819
- Sponsor's protocol ID
- IRB24-1178
- Status last verified
- Feb 2026
- First submitted
- 11 Feb 2025
- Last updated
- 2 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 2 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- DETERMINING THE IMPACT OF MICROBIAL DYSBIOSIS ON IMMUNE AND BARRIER DYSFUNCTION IN LONG COVID
- ClinicalTrials.gov ID
- NCT06825819
- Acronym / sponsor ID
- IRB24-1178
- Conditions
- COVID-19
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- University of ChicagoUniversity, hospital or other
- Study start
- 21 Jan 2025 (actual)
- Primary completion
- Jan 2029 (estimated)
- Study completion
- Jan 2029 (estimated)
- First posted
- 13 Feb 2025 (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.
The SARS-CoV-2 virus causes COVID-19, which ranges from mild initial symptoms to severe multi-organ dysfunction. While some patients recover to their baseline states, others develop a long COVID, or post-acute sequelae of SARS-CoV-2 (PASC) consisting of symptoms persisting >2-6 months post-infection. PASC symptoms include post-exertional malaise, fatigue, and heart palpitations as well as incident GI disorders, cognitive dysfunction, and arthritis. Based on prevalence/incidence studies, it is estimated that more than 30 million people in the US have ever developed PASC with 10-11% of patients or 11 million people continuing to feel symptoms to the present day10. SARS-CoV-2 vaccines are only ~32% effective against infection at 4 months post-vaccination11, only 15% effective against the development of PASC12, and only 20% of American adults have received an updated booster as of December 202313. It is therefore imperative that the scientific community make progress in identifying underlying causes of PASC to develop effective treatments.
This study will identify microbial metabolites associated with PASC-mediated gut dysbiosis and establish a tractable in vitro model to test T cell-gut epithelium dynamics to develop novel bio-therapeutics for multiple post-viral conditions. This case-control study will collect biospecimens (matched stool \& blood) samples from 400 people with and without long COVID (200 participants/group) to understand how COVID-induced dysbiosis impacts symptom severity, immune suppression, and gut barrier dysfunction both ex vivo and in vitro.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Subjects without Long COVID symptoms | – | Biological: Subjects with and without Long COVIDWe will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community without long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. |
| Subjects with Long COVID symptoms | – | Biological: Subjects with and without Long COVIDWe will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community with long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- We will enroll non-hospitalized patients recruited through the UCM long COVID clinic (headed by Dr. Rasika Karnik) and through the UCM Dept. of Gastroenterology endoscopy center under the umbrella Genesys protocol. We will also enroll convalescent subjects from the community with and without long COVID symptoms (only blood and stool samples collected from community participants, and they need not consent to the Genesys study to participate). All subjects will have had at least 1 PCR- or antigen-confirmed COVID-19 infection within the past 3 years and will be at least 60 days from their last SARS-CoV-2 infection. We will recruit a total of 400 subjects (200 ea. w/ and w/o long COVID). The research will be conducted at UCM clinic sites and in laboratory facilities
Key inclusion criteria (7 listed)
- Age: 18-80
- Sex: Any
- Race: Any
- Last COVID infection: within past 3 years, PCR- or antigen-confirmed, symptomatic (mild/moderate/severe)
- COVID vaccination status: Any
Key exclusion criteria (12 listed)
- Age <18 or >80
- Last COVID infection >3 years ago (PCR/antigen-confirmed, symptomatic)
- Currently or within the last 3 months COVID+ by nasopharyngeal PCR/antigen test
- Currently diagnosed with cancer
- Currently pregnant (cannot take colon biopsy sample; only eligible for survey/blood \& stool collection)
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 |
|---|---|---|
| Subjects with and without Long COVIDTo collect biospecimens (matched stool \& blood) samples from 400 people with and without long COVID (200 participants/group) to understand how COVID-induced dysbiosis impacts symptom severity, immune suppression, and gut barrier dysfunction both ex vivo and in vitro. | Biological | Subjects with Long COVID symptoms, Subjects without Long COVID symptoms |
Primary outcome
To determine whether people with long COVID exhibit microbial dysbiosis characterized by decreased bacterial diversity, overgrowth of Bacteroides taxa, and lower SCFA, indole, and secondary bile acid production with biospecimen collections
Time frame: At baseline until final values
1 secondary outcome
To collect matched stool, blood, and intestinal biopsy samples from a cohort of 300 individuals with and without long COVID (150/group)
Time frame: At baseline until final values
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Mar 2026.
- Individual participant dataSharing planned: Undecided
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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.
Lavanya Visvabharathy, Ph.D principal investigator
University of Chicago
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19, run by University of Chicago 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 7 inclusion and 12 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: looking for participants now, as of the sponsor's last update on 2 Mar 2026. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lavanya Visvabharathy, Ph.D (773-834-5087, lavanya.visvabharathy@bsd.uchicago.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine whether people with long COVID exhibit microbial dysbiosis characterized by decreased bacterial diversity, overgrowth of Bacteroides taxa, and lower SCFA, indole, and secondary bile acid production with biospecimen collections (time frame: At baseline until final values). 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 2 Mar 2026; AzTrials last refreshed its copy on 6 Nov 2026.