A new study has shown that people who have asthma or sniffling caused by allergies also carry a different set of fungi in their nasal cavities compared to people who do not experience allergy-related respiratory problems. This research was based on data collected from Portuguese adults, and has been reported in Frontiers in Microbiology.
Many people have a runny nose because of allergies, a problem that is sometimes known as allergic rhinitis. The symptoms usually include inflammation in the nasal mucous membranes, sneezing, itching, and a stuffy or runny nose. Allergic rhinitis is also associated with asthma. Scientists wanted to know more about the characteristics of the fungi in the nose, or nasal mycobiome, of people with or without this issue.
Since people with allergic rhinitis have a much higher level of fungal diversity in their noses, and a different structure in the nose mycobiome, noted study co-author Dr. Luís Delgado of the University of Porto. Delgadi also suggested that allergic rhinitis may be causing these changes.
In this work, the researchers collected data from 214 volunteers, 155 of whom had asthma and allergic rhinitis, while another 47 had allergic rhinitis alone, and a dozen people only had asthma. Another 125 unaffected individuals were also studied.
The researchers collected samples with nasal swabs, and identified the fungi in the samples by performing genetic sequencing. Each participant's nasal mycobiome was characterized in this way. There were 306 samples of high enough quality for inclusion in the study.
The investigators determined that Ascomycota and Basidiomycota fungi were most common, with fourteen different genera found at the highest levels in the mycobiomes. There were also major differences between people with respiratory issues and healthy controls. While the different groups of patients did not display significant differences between each other, these mycobiomes were much more diverse with many more species compared to healthy people.
"Among these dominant genera we detected common fungi that have been recognized 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."
Patients with respiratory problems displayed an enrichment in three metabolic pathways as well, which may serve as drug targets in the future. Much more research will be needed to confirm these results and understand the implications, however.
Delgado also added that certain variables like disease severity were not controlled for, and everyone was sampled at the same time. The researchers also don't know how the nasal mycobiome may be changing in people over time, or whether the fungi play a role in disease development or symtoms. This field is poised to grow, and investigate how common fungi may be affecting human health.
