Salivary Metabolomics in Patients with Long COVID-19 Infection

Area of Science:

• Biochemistry
• Metabolomics
• Post-COVID Conditions

Background:

• Long COVID-19 is defined by symptoms persisting over 4 weeks post-acute infection.
• The underlying pathophysiology of long COVID clinical manifestations remains poorly understood.
• Investigating metabolic changes offers potential insights into long COVID pathophysiology.

Purpose of the Study:

• To assess salivary metabolite abundance in long COVID patients 60 days after hospital discharge.
• To identify potential biomarkers associated with long COVID symptoms and pathophysiology.
• To compare metabolite profiles between long COVID patients and non-COVID-19 controls.

Main Methods:

• Saliva metabolomics analysis was performed on 30 post-discharge long COVID patients and 7 healthy controls.
• Long COVID patients underwent comprehensive clinical evaluations including spirometry, 6-minute walk test (6mWT), and respiratory questionnaires.
• Statistical analysis identified differentially expressed metabolites between the two groups.

Main Results:

• Metabolomics revealed 19 differentially expressed metabolites in long COVID patients compared to controls.
• Sixteen metabolites showed lower abundance, and 2 were absent in long COVID patients.
• Significantly lower levels of calenduloside G methyl ester, Gly Pro Lys, and creatine were observed in long COVID patients.

Conclusions:

• Long COVID patients exhibit distinct salivary metabolite profiles compared to healthy individuals.
• Reduced abundance of specific metabolites, particularly creatine, may be associated with long COVID-related fatigue and reduced physical capacity.
• Salivary metabolomics holds promise for understanding and potentially diagnosing long COVID.