Covid19NCT04813718
Post COVID-19 Syndrome and the Gut-lung Axis
A study testing Omni-Biotic Pro Vi 5 in people with Covid19, run by Medical University of Graz at 1 site in Austria.
Trial summary
The outbreak of the novel coronavirus (SARS-CoV-2)-infected disease (COVID-19) began in December 2019, spread throughout China in early 2020 and developed as a pandemic thereafter. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Covid19
- What is being tested?
- Omni-Biotic Pro Vi 5
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 21 participants
- Where
- 1 siteAustria
- Study dates
- 2 Jun 2021to 31 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 18 years or older
- Covid-19 infection with severe disease defined within the last 12 months (defined as one or more of the following: hospitalization, need for oxygen supply, need for intensive care treatment, need for specific treatment of Covid disease, antibiotic treatment)
- Subjective presence of residual symptoms of Covid disease OR no residual symptoms of Covid disease (Controls)
- Informed consent
Who cannot join
- Continuous probiotic treatment in the last 4 weeks before inclusion
- Pre-existing lung diseases
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Post COVID-19 Syndrome: A Pilot Study to Explore the Gut-lung Axis
The outbreak of the novel coronavirus (SARS-CoV-2)-infected disease (COVID-19) began in December 2019, spread throughout China in early 2020 and developed as a pandemic thereafter.
Based on current knowledge, Covid-19 infection causes mild to moderate respiratory and gastrointestinal symptoms in the majority of patients. In a smaller percentage severe disease courses are observed, often with the need of hospitalization and intensive care treatment. Apparently, symptoms can persist for relatively long time after viral clearance, suggesting the existence of a "Post-Covid" syndrome. A study from the UK identified fatigue, breathlessness and psychosocial stress as common symptoms after discharge from the hospital. Covid-19 infection is frequently characterized by a hyperinflammatory phenotype and a cytokine storm. The Covid-19 cytokine storm is characterised by rapid proliferation and hyperactivation of T cells, macrophages, mast cells, neutrophil granulocytes and natural killer cells, and the overproduction of inflammatory cytokines and chemical mediators released by immune or nonimmune cells. Early data also suggest that even if symptoms are just 'mild to moderate' during the acute infection, fibrotic lung damage develops in some patients. This may lead to long-term pulmonary complications for a subset of patients. The mechanisms for post-Covid pulmonary fibrosis are still unclear: inflammation triggering fibrosis, epithelial and endothelial injury with inadequate fibroproliferation and vascular damage are considered to be possible mechanisms.
Read more
A potential therapeutic target in ameliorating post-Covid symptoms could be the gut microbiome. Gut microbiome alterations have been described in Covid-19. The gut-lung axis as a link between dysbiosis, barrier dysfunction, translocation of bacterial products and hyperinflammation has been proposed as a potential therapeutic target. Probiotics have been proposed to be a possible modulator of the deranged gut-lung axis in Covid-disease and post-Covid syndrome. Currently 11 studies are registered in clinicaltrials.gov for treatment of acute Covid disease and prevention of the disease (including one study from Graz), but no study related to post-Covid syndrome could be found.
Therefore, it is currently unclear, which clinical, immune system or microbiome related biomarker would be the best to study the effect of a microbiome-based intervention in post-Covid syndrome.
- Conditions
- Covid19
- Being tested
- Omni-Biotic Pro Vi 5, Placebo
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Omni-Biotic Pro Vi 5Dietary supplement
Pre- and probiotic
PlaceboDietary supplement
Placebo
| Study group | Role | What they receive |
|---|---|---|
| Synbiotic | Active comparator | Omni-Biotic Pro Vi 5 Receives: Dietary Supplement: Omni-Biotic Pro Vi 5 |
| Placebo | Placebo comparator | similar looking and tasting Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Microbiome composition
16 sRNA sequencing
Measured: 6 months
Intestinal barrier
Change in zonulin levels over time and with/without the intervention
Measured: 6 months
sCD14
Change in sCD14 levels over time and with/without the intervention
Measured: 6 months
endotoxin
Change in endotoxin levels serum over time and with/without the intervention
Measured: 6 months
TNFalpha
Change in TNFalpha levels serum over time and with/without the intervention
Measured: 6 months
Interleukin 1b
Change in Interleukin 1b serum levels over time and with/without the intervention
Measured: 6 months
Interleukin 6
Change in interleukin 6 serum levels over time and with/without the intervention
Measured: 6 months
Interleukin 6 receptor
Change in Interleukin 6 receptor serum levels over time and with/without the intervention
Measured: 6 months
interleukin 8
Change in interleukin 8 serum levels over time and with/without the intervention
Measured: 6 months
interleukin 10
Change in interleukin 10 serum levels over time and with/without the intervention
Measured: 6 months
interleukin 17
Change in interleukin 17 serum levels over time and with/without the intervention
Measured: 6 months
interleukin 23
Change in interleukin 23 serum levels over time and with/without the intervention
Measured: 6 months
neutrophil function burst function
Change in neutrophil burst function over time and with/without the intervention
Measured: 6 months
neutrophil function phagocytosis
Change in neutrophil phagocytosis function over time and with/without the intervention
Measured: 6 months
neutrophil NET formation
Change in neutrophil NET formation over time and with/without the intervention
Measured: 6 months
neutrophil surface receptor expression
Change in neutrophil surface receptor expression over time and with/without the intervention
Measured: 6 months
monocyte burst
Change in monocyte burst over time and with/without the intervention
Measured: 6 months
monocyte phagocytosis
Change in monocyte phagocytosis over time and with/without the intervention
Measured: 6 months
monocyte function surface receptor expression
Change in monocyte surface receptor expression over time and with/without the intervention
Measured: 6 months
T cell immunophenotyping
Change in T cell subtypes over time and with/without the intervention
Measured: 6 months
B cells immunophenotyping
Change in B cell subtypes over time and with/without the intervention
Measured: 6 months
Spirometry
Change in spirometry measurements over time and with/without the intervention
Measured: 6 months
Lung volume
Change in lung volume over time and with/without the intervention
Measured: 6 months
Gas diffusion
Change in pulmonary gas diffusion over time and with/without the intervention
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Mar 2021
- Study start2 Jun 2021
- Primary completion11 Jul 2022
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Covid19Studies of the same condition, open and under way.
- More trials run by Medical University of GrazThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 21 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of Graz
- Sponsor type
- University, hospital or other
- Collaborators
- CBmed Ges.m.b.H.
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04813718
- Sponsor's protocol ID
- PostCov
- Status last verified
- Nov 2025
- First submitted
- 15 Mar 2021
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data will be shared upon reasonable request
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Post COVID-19 Syndrome: A Pilot Study to Explore the Gut-lung Axis
- ClinicalTrials.gov ID
- NCT04813718
- Acronym / sponsor ID
- PostCov
- Conditions
- Covid19
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 21 participants (actual)
- Lead sponsor
- Medical University of GrazUniversity, hospital or other
- Collaborators
- CBmed Ges.m.b.H.
- Study start
- 2 Jun 2021 (actual)
- Primary completion
- 11 Jul 2022 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 24 Mar 2021 (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 outbreak of the novel coronavirus (SARS-CoV-2)-infected disease (COVID-19) began in December 2019, spread throughout China in early 2020 and developed as a pandemic thereafter.
Based on current knowledge, Covid-19 infection causes mild to moderate respiratory and gastrointestinal symptoms in the majority of patients. In a smaller percentage severe disease courses are observed, often with the need of hospitalization and intensive care treatment. Apparently, symptoms can persist for relatively long time after viral clearance, suggesting the existence of a "Post-Covid" syndrome. A study from the UK identified fatigue, breathlessness and psychosocial stress as common symptoms after discharge from the hospital. Covid-19 infection is frequently characterized by a hyperinflammatory phenotype and a cytokine storm. The Covid-19 cytokine storm is characterised by rapid proliferation and hyperactivation of T cells, macrophages, mast cells, neutrophil granulocytes and natural killer cells, and the overproduction of inflammatory cytokines and chemical mediators released by immune or nonimmune cells. Early data also suggest that even if symptoms are just 'mild to moderate' during the acute infection, fibrotic lung damage develops in some patients. This may lead to long-term pulmonary complications for a subset of patients. The mechanisms for post-Covid pulmonary fibrosis are still unclear: inflammation triggering fibrosis, epithelial and endothelial injury with inadequate fibroproliferation and vascular damage are considered to be possible mechanisms.
A potential therapeutic target in ameliorating post-Covid symptoms could be the gut microbiome. Gut microbiome alterations have been described in Covid-19. The gut-lung axis as a link between dysbiosis, barrier dysfunction, translocation of bacterial products and hyperinflammation has been proposed as a potential therapeutic target. Probiotics have been proposed to be a possible modulator of the deranged gut-lung axis in Covid-disease and post-Covid syndrome. Currently 11 studies are registered in clinicaltrials.gov for treatment of acute Covid disease and prevention of the disease (including one study from Graz), but no study related to post-Covid syndrome could be found.
Therefore, it is currently unclear, which clinical, immune system or microbiome related biomarker would be the best to study the effect of a microbiome-based intervention in post-Covid syndrome.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Synbiotic | Active comparator | Dietary Supplement: Omni-Biotic Pro Vi 5Omni-Biotic Pro Vi 5 |
| Placebo | Placebo comparator | Dietary Supplement: Placebosimilar looking and tasting |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 18 years or older
- Covid-19 infection with severe disease defined within the last 12 months (defined as one or more of the following: hospitalization, need for oxygen supply, need for intensive care treatment, need for specific treatment of Covid disease, antibiotic treatment)
- Subjective presence of residual symptoms of Covid disease OR no residual symptoms of Covid disease (Controls)
- Informed consent
Key exclusion criteria (2 listed)
- Continuous probiotic treatment in the last 4 weeks before inclusion
- Pre-existing lung diseases
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 |
|---|---|---|
| Omni-Biotic Pro Vi 5Pre- and probiotic | Dietary supplement | Synbiotic |
| PlaceboPlacebo | Dietary supplement | Placebo |
Primary outcome
Microbiome composition
Time frame: 6 months
16 sRNA sequencing
Intestinal barrier
Time frame: 6 months
Change in zonulin levels over time and with/without the intervention
sCD14
Time frame: 6 months
Change in sCD14 levels over time and with/without the intervention
endotoxin
Time frame: 6 months
Change in endotoxin levels serum over time and with/without the intervention
TNFalpha
Time frame: 6 months
Change in TNFalpha levels serum over time and with/without the intervention
Interleukin 1b
Time frame: 6 months
Change in Interleukin 1b serum levels over time and with/without the intervention
Interleukin 6
Time frame: 6 months
Change in interleukin 6 serum levels over time and with/without the intervention
Interleukin 6 receptor
Time frame: 6 months
Change in Interleukin 6 receptor serum levels over time and with/without the intervention
interleukin 8
Time frame: 6 months
Change in interleukin 8 serum levels over time and with/without the intervention
interleukin 10
Time frame: 6 months
Change in interleukin 10 serum levels over time and with/without the intervention
interleukin 17
Time frame: 6 months
Change in interleukin 17 serum levels over time and with/without the intervention
interleukin 23
Time frame: 6 months
Change in interleukin 23 serum levels over time and with/without the intervention
neutrophil function burst function
Time frame: 6 months
Change in neutrophil burst function over time and with/without the intervention
neutrophil function phagocytosis
Time frame: 6 months
Change in neutrophil phagocytosis function over time and with/without the intervention
neutrophil NET formation
Time frame: 6 months
Change in neutrophil NET formation over time and with/without the intervention
neutrophil surface receptor expression
Time frame: 6 months
Change in neutrophil surface receptor expression over time and with/without the intervention
monocyte burst
Time frame: 6 months
Change in monocyte burst over time and with/without the intervention
monocyte phagocytosis
Time frame: 6 months
Change in monocyte phagocytosis over time and with/without the intervention
monocyte function surface receptor expression
Time frame: 6 months
Change in monocyte surface receptor expression over time and with/without the intervention
T cell immunophenotyping
Time frame: 6 months
Change in T cell subtypes over time and with/without the intervention
B cells immunophenotyping
Time frame: 6 months
Change in B cell subtypes over time and with/without the intervention
Spirometry
Time frame: 6 months
Change in spirometry measurements over time and with/without the intervention
Lung volume
Time frame: 6 months
Change in lung volume over time and with/without the intervention
Gas diffusion
Time frame: 6 months
Change in pulmonary gas diffusion over time and with/without the intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- Individual participant dataSharing planned: No. Data will be shared upon reasonable request
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Omni-Biotic Pro Vi 5 in people with Covid19, run by Medical University of Graz at 1 site in Austria.
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 4 inclusion and 2 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: finished, as of the sponsor's last update on 13 Oct 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 Austria. 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. Some participants in this study may receive a placebo. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Microbiome composition (time frame: 6 months). The study lists 24 primary outcomes in all. 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 13 Oct 2026.