Post COVID-19 Syndrome and the Gut-lung Axis

NCT04813718 | Active Not Recruiting

• 1 other identifier: PostCov
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

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.

Conditions

Covid19

Outcome Measures

Primary Outcomes (24)

• Microbiome composition

  16 sRNA sequencing

  6 months

• Intestinal barrier

  Change in zonulin levels over time and with/without the intervention

  6 months

• sCD14

  Change in sCD14 levels over time and with/without the intervention

  6 months

• endotoxin

  Change in endotoxin levels serum over time and with/without the intervention

  6 months

• TNFalpha

  Change in TNFalpha levels serum over time and with/without the intervention

  6 months

• Interleukin 1b

  Change in Interleukin 1b serum levels over time and with/without the intervention

  6 months

• Interleukin 6

  Change in interleukin 6 serum levels over time and with/without the intervention

  6 months

• Interleukin 6 receptor

  Change in Interleukin 6 receptor serum levels over time and with/without the intervention

  6 months

• interleukin 8

  Change in interleukin 8 serum levels over time and with/without the intervention

  6 months

• interleukin 10

  Change in interleukin 10 serum levels over time and with/without the intervention

  6 months

• interleukin 17

  Change in interleukin 17 serum levels over time and with/without the intervention

  6 months

• interleukin 23

  Change in interleukin 23 serum levels over time and with/without the intervention

  6 months

• neutrophil function burst function

  Change in neutrophil burst function over time and with/without the intervention

  6 months

• neutrophil function phagocytosis

  Change in neutrophil phagocytosis function over time and with/without the intervention

  6 months

• neutrophil NET formation

  Change in neutrophil NET formation over time and with/without the intervention

  6 months

• neutrophil surface receptor expression

  Change in neutrophil surface receptor expression over time and with/without the intervention

  6 months

• monocyte burst

  Change in monocyte burst over time and with/without the intervention

  6 months

• monocyte phagocytosis

  Change in monocyte phagocytosis over time and with/without the intervention

  6 months

• monocyte function surface receptor expression

  Change in monocyte surface receptor expression over time and with/without the intervention

  6 months

• T cell immunophenotyping

  Change in T cell subtypes over time and with/without the intervention

  6 months

• B cells immunophenotyping

  Change in B cell subtypes over time and with/without the intervention

  6 months

• Spirometry

  Change in spirometry measurements over time and with/without the intervention

  6 months

• Lung volume

  Change in lung volume over time and with/without the intervention

  6 months

• Gas diffusion

  Change in pulmonary gas diffusion over time and with/without the intervention

  6 months

Study Arms (2)

Synbiotic

ACTIVE COMPARATOR

Omni-Biotic Pro Vi 5

Dietary Supplement: Omni-Biotic Pro Vi 5

Placebo

PLACEBO COMPARATOR

similar looking and tasting

Dietary Supplement: Placebo

Interventions

Omni-Biotic Pro Vi 5 DIETARY_SUPPLEMENT

Pre- and probiotic

Synbiotic

Placebo DIETARY_SUPPLEMENT

Placebo

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• Pre-existing lung diseases

Sponsors & Collaborators

• Medical University of Graz: lead
• CBmed Ges.m.b.H.: collaborator

Study Sites (1)

Medical University Graz

Graz, Austria

Location

MeSH Terms

Conditions

COVID-19

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 15, 2021
• First Posted: March 24, 2021
• Study Start: June 2, 2021
• Primary Completion: July 11, 2022
• Study Completion: December 1, 2025
• Last Updated: November 25, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1)