Have you heard of the pulmonary microbiota, which may also be referred to as the lung microbiome? This refers to the complex collection of microorganisms (bacteria, viruses, bacteriophages, fungi) that live within the respiratory tract. According to an article from Marisa Wexler in Sarcoidosis News, a new study suggests that dysbiosis (imbalance) within the pulmonary microbiome could play a role in sarcoidosis development. The study found that those with sarcoidosis have a less diverse and more poorly balanced microbiota than healthy individuals. 

Expanding on Research

Within the study, published in Microbiome, the research team sought to understand the relationship between sarcoidosis and fungi and bacteria within the microbiota. Altogether, 70 participants enrolled. 35 of these participants were healthy controls while the other 35 had sarcoidosis. These participants were all involved in The Microbiome in Interstitial Lung Disease study and The Bergen Chronic Obstructive Pulmonary Disease Microbiome study. 

Researchers sourced fluid samples from the participants’ mouths and lungs using a bronchoscopy. Additional RNA sequencing was also performed. Findings from the study include:

• People with sarcoidosis had higher levels of Aspergillus in their lungs, as well as other Eurotiomycetes fungi. These fungi were not found in the lungs of healthy individuals. 
• Candida fungi were more likely to be found in healthy controls than in the lungs of people with sarcoidosis.
• Those with sarcoidosis also had lower levels of antimicrobial peptides that could help the body to fight infections or other illnesses. 
• People with sarcoidosis also had less diverse bacterial presence in their lungs.

This expands on prior research which found that people with sarcoidosis had higher amounts of antifungal antibodies. Researchers hypothesize that these antibodies could be the result of frequent fungal infections. Further, researchers wonder if a fungal infection could potentially trigger or cause sarcoidosis development. 

Ultimately, more research is needed: both on the dysbiosis within the lungs of people with sarcoidosis and on whether this dysbiosis could actually cause the disease. 

Sarcoidosis: An Overview

In healthy individuals, the immune system effectively protects the body against harmful substances, foreign invaders, or other potentially disease-causing agents. But in people with sarcoidosis, the immune system overreacts, causing inflammation. Excess immune cells form granulomas (lumps) throughout the body. Sarcoidosis most often originates in the lymph nodes, lungs, or skin, though it can also affect the eyes, heart, and nervous system. Over 50% of people with sarcoidosis enter into remission within three years following sarcoidosis. This disorder is more common (and often more severe) in patients of African-American descent.

Symptoms can, but do not always, include:

• Fatigue
• Swollen lymph nodes
• Shortness of breath
• Unintentional weight loss
• Joint pain and swelling
• Blurred vision
• Eye redness, pain, burning, itching, or dryness 
• Lesions on the ears, nose, and cheeks
• Nodules around scars or tattoos
• Chest pain
• Recurrent coughing or wheezing

Treatment options may include antimalarial medications, prednisone, or immunosuppressants. Not every individual with sarcoidosis will require treatment.