NCT06825819 · University of Chicago
Dysbiosis & Long COVID
What this study is about
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.
View original scientific description
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.
Interventions
BIOLOGICAL
Subjects with and without Long COVID
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.
Primary outcome measures
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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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
Exclusion criteria
- 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
- 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
Where
- Chicago, Illinois
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 2, 2026 · Source of record for eligibility and locations