Study reveals nasal fungi diversity in allergy and asthma patients

Nearly a quarter of Portuguese adults have allergies that cause a runny nose. This respiratory disease, formally called allergic rhinitis and frequently associated with asthma, is a common problem around the world, and the upper airway is a key target for research into the underlying disease processes. Now a global team of researchers has discovered that patients with allergy-induced sniffles and asthma have different fungal colonies or mycobiomes in their noses, suggesting potential lines of enquiry for future treatments.

A miniature mycological world 

Allergic rhinitis causes sneezing, itching, inflamed nasal mucous membranes, and a blocked and runny nose. It's often comorbid with asthma, which also involves inflammation and obstructed airways. Allergic rhinitis and asthma may even be different aspects of the same airway inflammatory disease, which makes it critical to identify the links between them and the underlying causes.

The scientists took samples from the participants' noses using nasal swabs and sequenced the fungal DNA they found, focusing on two specific regions to identify different fungal species and develop an overview of each participant's mycobiome. After quality controls, they had 306 samples to work with.

They then used network analysis to understand the relationships between different genera of fungi, and to characterize the different communities of fungi present in healthy and sick participants. They also investigated the function of different fungi, looking at the metabolic pathways they affect, to try to understand the implications of any mycobiome variation between the groups of patients.

Coughs and sneezes 

There was a very clear and statistically significant difference between the patients with respiratory diseases and the healthy controls – and no significant difference between the different groups of patients with respiratory diseases. The patients with respiratory diseases had more diverse and richer mycobiomes. The fungi sampled from patients with both allergic rhinitis and asthma also showed more evidence of connections between them than the fungi in the healthy participants' noses and those who only had allergic rhinitis. This could indicate that the fungi are affecting the nose's immune environment.

Source:

Frontiers

Journal reference:

The nasal mycobiome of individuals with allergic rhinitis and asthma differs from that of healthy controls in composition, structure and function. doi.org/10.3389/fmicb.2024.1464257.