Titel

The Airborne and Oral Microbiome in Relation to Allergy, Asthma and Chronic Rhinosinusitis.

Tid

Tirsdag den 27. juni 2025 kl. 14 

Sted

Aarhus Universitet, Samfundsmedicinsk Auditorium, Bygning 1262, lokale 101, Bartholins Allé 4, 8000 Århus C.

Forsvaret holdes på engelsk.  

Se invitation

Resumé

Research has long suggested that the microbiome plays a role in the development of allergies and respiratory diseases. However, most studies so far have focused on children or specific patient groups. In her PhD project, Christine Wulff Cramer investigated how the airborne and oral microbiome are related to allergy, asthma, and chronic rhinosinusitis (CRS) among adults in a large international population-based study. 

As part of the European Community Respiratory Health Survey (ECRHS), microbiome samples werecollected from the bedrooms of more than 1000 participants across five countries and analyzed using DNA sequencing techniques. In addition, oral microbiome samples were collected from participants in Norway, Estonia, and Australia. 

The study found no clear association between microbial diversity in indoor air and current respiratory diseases. However, in a 10-year follow-up, greater microbial diversity in the home was associated with 

worsening respiratory symptoms over time. Increased bacterial and endotoxin load in indoor air was also linked to asthma, CRS, and respiratory symptoms. In the oral microbiome, greater diversity was associated with lower lung function and non-allergic CRS. Several microbial species and gene functions were more common among individuals without asthma, CRS, or allergies — suggesting that both the composition and function of the microbiome, rather than diversity alone, may be important for respiratory health. 

This is the first large-scale, population-based study to examine both the airborne and oral microbiome in relation to adult respiratory health. While the results cannot be translated directly into clinical guidelines, they underline that childhood is probably the critical period for the influence of microbial exposure on respiratory health — but also suggest that high bacterial load in indoor air may be harmful to adults.   

Bedømmelsesudvalget 

Bodil Hammer Bech, Associate professor (formand for bedømmelsesudvalget), Aarhus Universitet 

Lidwien Smit, Professor, Utrecht University, Holland 

Allan Linneberg, Professor, Frederiksberg Hospital, Københavns Universitet 

Vivi Schlünssen, Professor (hovedvejleder), Aarhus Universitet