Different fungi groups behind allergy-induced sniffles, asthma: Study

People with allergy-induced sniffles and asthma may have different fungal colonies or mycobiomes in their noses, finds a study on Tuesday.

The common respiratory disease, formally called allergic rhinitis, has frequently been associated with asthma. Typical symptoms of allergic rhinitis include 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.

Researchers from the University of Porto, Portugal, showed that this association may be because of different fungal colonies or mycobiomes in their noses.

“We showed that allergic rhinitis samples displayed a significantly higher fungal diversity and a different fungal community structure compared to those of healthy controls,” said Dr. Luís Delgado of the University of Porto.

“This may suggest that allergic rhinitis increases the diversity and changes the composition of the upper airway’s microbiome.”

To study the nasal mycobiome, the researchers recruited 214 participants among children and young adults attending an immunology and asthma clinic in Porto. About 155 patients had both allergic rhinitis and asthma, while 47 were only diagnosed with allergic rhinitis and 12 with asthma. The team also enrolled 125 healthy controls.

The team analysed 306 samples, taken via nasal swabs. DNA sequencing revealed Ascomycota and Basidiomycota as the most common fungi families across all samples. In these two families, 14 genera dominated the mycobiomes.

“Among these dominant genera we detected common fungi that have been recognised in humans as allergenic or opportunistic pathogenic fungi,” said Delgado. “This suggests that the nasal cavity is a major reservoir for fungi that could be involved in allergic rhinitis and asthma.”

The findings, published in an article in the Frontiers in Microbiology journal, showed a very clear and statistically significant difference between the patients with respiratory diseases as well as the healthy controls.

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, the researchers said.