Respiratory dysfunction three months after severe COVID-19 is associated with gut microbiota alterations

Area of Science:

• Microbiology
• Pulmonology
• Gastroenterology

Background:

• Coronavirus disease 2019 (COVID-19) primarily affects the respiratory system but involves the gastrointestinal tract.
• Gut barrier dysfunction and microbiota alterations correlate with COVID-19 severity.
• The persistence of these gut changes and their link to long-term respiratory issues remain unclear.

Purpose of the Study:

• To investigate persistent gut microbiota alterations and gut barrier dysfunction in COVID-19 patients.
• To determine the association between these gut changes and long-term respiratory dysfunction.

Main Methods:

• Collected plasma and rectal swabs from COVID-19 patients during hospitalization and at 3-month follow-up.
• Assessed gut barrier dysfunction markers (lipopolysaccharide-binding protein - LBP) and inflammation.
• Analyzed gut microbiota composition using 16S rRNA gene sequencing.
• Evaluated pulmonary function via diffusing capacity of the lungs for carbon monoxide (DLCO).

Main Results:

• Reduced gut microbiota diversity and altered composition were observed in patients with persistent respiratory dysfunction (low DLCO at 3 months).
• Elevated plasma LBP levels during hospitalization strongly correlated with respiratory failure (low P/F ratio).
• LBP levels remained elevated post-hospitalization, associated with inflammation and 3-month respiratory dysfunction.

Conclusions:

• Persistent respiratory dysfunction after COVID-19 is linked to altered gut microbiota and sustained elevated LBP levels.
• Findings suggest a potential gut-lung axis influencing long-term pulmonary function and long COVID.
• Further research is warranted to explore this gut-lung connection in post-COVID-19 respiratory complications.