A new study on the role of the nasal microbiome could point to a non-invasive diagnostic route for a rare nasal disorder called eosinophilic chronic rhinosinusitis with nasal polyps.
Picture this: a never-ending stuffy nose, trouble breathing through your nostrils, constant face discomfort, and a fading sense of smell. That is what happens when you have chronic rhinosinusitis, a condition in which the inside of your nose and sinuses stay irritated for a long time, usually over 12 weeks.
Sometimes, those with the condition may also face small growths inside their nose or sinus, a variant called chronic rhinosinusitis with nasal polyps. These nasal polyps make it difficult to breathe through your nose, causing facial discomfort, and taking away the ability to smell things properly. A variant of this, called eosinophilic chronic rhinosinusitis with nasal polyps, is harder to manage as it involves an abnormal increase in white blood cells called eosinophils inside the nose and sinuses.
The study by the Institute of Otolaryngology of Tianjin, China, published in The Journal of Allergy and Clinical Immunology identified a link between eosinophilic chronic rhinosinusitis and imbalances in the nasal microbiome.
Dr Rohit Gaurav, a Principal Scientist at the Novartis Institutes for Biomedical Research in the United States, tells Happiest Health that these imbalances can incite inflammation, disrupt mucosal barriers, and promote eosinophilic inflammation.
However, he notes that the precise mechanisms “connecting nasal microbiome imbalances to the development of eosinophilic chronic rhinosinusitis are not yet fully understood.”
Finding a nasal microbiome link with eosinophilic chronic rhinosinusitis
The study examined those who had chronic rhinosinusitis with and without nasal polyps and those with the eosinophilic variant for which they looked at nasal bacterial samples and compared the differences. According to the author of the study, eosinophilic chronic rhinosinusitis was associated with “significantly increased intraindividual bacterial diversity and alterations in taxonomic composition, which are linked to disease severity.”
That means, eosinophilic chronic rhinosinusitis with nasal polyps is connected to a higher diversity of bacteria within an individual and changes in the types of bacteria present, which are related to how severe the condition is.
One of the study’s breakthroughs was the identification of a unique microbial signature within the nasal microbiome that could aid in diagnosing and predicting the progression of eosinophilic chronic rhinosinusitis. Distinguishing eosinophilic chronic rhinosinusitis from other forms of chronic rhinosinusitis has historically posed challenges, however, this study identified 15 specific bacterial genera that effectively differentiated individuals with eosinophilic variants from healthy controls. This could become marker for eosinophilic chronic rhinosinusitis diagnosis and prognosis.
However, the researchers noted that further investigations are necessary to understand the role of specific microbial species like Staphylococcus aureus and Corynebacterium species, in the development of eosinophilic chronic rhinosinusitis.
The need to study nasal microbiome interventions
The study’s findings have opened the door to potential interventions targeting the nasal microbiome, such as probiotics or microbial-based therapies, offering hope for the improved management of eosinophilic chronic rhinosinusitis. The diagnostic method does not necessitate invasive procedures like surgery or tissue sampling; instead, it relies on analysing the nasal microbiome, which can be obtained through less invasive methods, such as nasal secretions or swabs.
Dr Gaurav also pointed out that lifestyle and environmental factors including diet, hygiene, smoking, indoor air quality, and antibiotic use, may influence the composition of the nasal microbiome. This consequently affects the eosinophilic chronic rhinosinusitis symptoms.
Further research on the link between the nasal microbiome and eosinophilic chronic rhinosinusitis may lead to more effective diagnosis, prognosis, and treatment options for those suffering from this challenging condition.