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Post COVID-19 Syndrome and the Gut-lung Axis

Post COVID-19 Syndrome: A Pilot Study to Explore the Gut-lung Axis

Status
Active, not recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04813718
Enrollment
20
Registered
2021-03-24
Start date
2021-06-02
Completion date
2025-12-31
Last updated
2025-11-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Covid19

Brief 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. 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.

Interventions

DIETARY_SUPPLEMENTOmni-Biotic Pro Vi 5

Pre- and probiotic

DIETARY_SUPPLEMENTPlacebo

Placebo

Sponsors

CBmed Ges.m.b.H.
CollaboratorOTHER
Medical University of Graz
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* 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

Exclusion criteria

* Continuous probiotic treatment in the last 4 weeks before inclusion * Pre-existing lung diseases

Design outcomes

Primary

MeasureTime frameDescription
Microbiome composition6 months16 sRNA sequencing
Intestinal barrier6 monthsChange in zonulin levels over time and with/without the intervention
sCD146 monthsChange in sCD14 levels over time and with/without the intervention
endotoxin6 monthsChange in endotoxin levels serum over time and with/without the intervention
TNFalpha6 monthsChange in TNFalpha levels serum over time and with/without the intervention
Interleukin 1b6 monthsChange in Interleukin 1b serum levels over time and with/without the intervention
Interleukin 66 monthsChange in interleukin 6 serum levels over time and with/without the intervention
Interleukin 6 receptor6 monthsChange in Interleukin 6 receptor serum levels over time and with/without the intervention
interleukin 86 monthsChange in interleukin 8 serum levels over time and with/without the intervention
interleukin 106 monthsChange in interleukin 10 serum levels over time and with/without the intervention
interleukin 176 monthsChange in interleukin 17 serum levels over time and with/without the intervention
interleukin 236 monthsChange in interleukin 23 serum levels over time and with/without the intervention
neutrophil function burst function6 monthsChange in neutrophil burst function over time and with/without the intervention
neutrophil function phagocytosis6 monthsChange in neutrophil phagocytosis function over time and with/without the intervention
neutrophil NET formation6 monthsChange in neutrophil NET formation over time and with/without the intervention
neutrophil surface receptor expression6 monthsChange in neutrophil surface receptor expression over time and with/without the intervention
monocyte burst6 monthsChange in monocyte burst over time and with/without the intervention
monocyte phagocytosis6 monthsChange in monocyte phagocytosis over time and with/without the intervention
monocyte function surface receptor expression6 monthsChange in monocyte surface receptor expression over time and with/without the intervention
T cell immunophenotyping6 monthsChange in T cell subtypes over time and with/without the intervention
B cells immunophenotyping6 monthsChange in B cell subtypes over time and with/without the intervention
Spirometry6 monthsChange in spirometry measurements over time and with/without the intervention
Lung volume6 monthsChange in lung volume over time and with/without the intervention
Gas diffusion6 monthsChange in pulmonary gas diffusion over time and with/without the intervention

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026