Airway and Oral Microbiomes Linked to Long COVID Severity
Linking airway bacteria to inflammation and multi-organ symptoms, the study urges trials to test microbiome-targeted interventions.
Overview
- A UK multicentre analysis of 771 people published in the European Respiratory Journal in October 2026 found distinct saliva and sputum microbiome patterns in patients with the most severe long COVID.
- Those with very severe symptoms showed an over-abundance of lactic-acid–producing bacteria that correlated with higher blood markers of inflammation.
- Microbiome changes were tied not only to reduced lung function but also to persistent cognitive problems such as brain fog and to gastrointestinal symptoms.
- Samples were taken about five to six months after hospital discharge for infections during February 2020–March 2021, so the study shows association but cannot prove the microbiome caused long COVID.
- Authors and outside experts say the results point to testable treatment ideas like probiotics or antibiotics and they call for longitudinal and mechanistic studies plus clinical trials to evaluate causation and safety.