The changing perception of asthma: How microbes are contributing to this disease

**Thanks asth.ma for posting our blog on September 8, 2015

Main Guest Author: Chris S. Earl, PhD

Contributing Guest Authors: Meaghan Lee-Erlandsen and Dr. Nora Khaldi of Nuritas™

Asthma is an inflammatory disease of the lower airway resulting in coughing, wheezing and chest tightness. Key features of asthma are periodic increases in severity of symptoms known as exacerbations as well as recurrent and persistent respiratory infections.

There are over 300 million people suffering from asthma across the globe resulting in extensive morbidity and staggering healthcare costs. Therefore, a better understanding of asthma is required in order to improve the lives of an ever increasing number of people. Historically, asthma has been thought of as an allergic disease, but surprisingly, only around 50% of asthmatics show signs of allergy (atopy). This is transforming the way we view the disease. It is now recognised that asthma is probably an umbrella term which encompasses a variety of conditions which although all having similar clinical presentation, in terms of symptoms, there is a diverse range of underlying immune responses at play.”

We at Nuritas™ recently read a review by Chris S. Earl, PhD and colleagues in the Cell journal (Trends in Microbiology) that discusses the contribution of airway microbes to asthma development and severity. To find out further details on this intriguing relationship, we decided to reach out to the author who was kind enough to provide us with the above information on the overall disease as well as a detailed summary of this groundbreaking work. Mr. Earl and his co-authors are based in the College of Life Sciences, Division of Molecular Microbiology, at the University of Dundee.

“In this review, my co-authors and I discuss the growing evidence for the role of microbes, which inhabit the airway (termed the airway microbiota) in eliciting immune responses that may contribute to the disease. Each day an individual breathes in >8000 litres of air, air which is full of microbial components and intact bacterial cells that could potentially cause disease or elicit an immune response. We describe how for a long time it was thought that the lungs were sterile but that there is an ever-increasing amount of work showing that there are bacteria that inhabit this environment, and examine the implications this has for our understanding of asthma. We highlight how it is very important for the immune system to keep microbes in check to protect the function of the lungs in gas exchange and how if these immune defences are erroneous in some individuals this could lead to uncontrolled inflammation.

Furthermore, we debate the different ways that an understanding of the airway microbiota and what these microbial communities are capable of can help to explain some of the subtypes of asthma that are as yet poorly understood, but also how bacterial communities may contribute to allergy through changes in the inflammatory profile of the airway.”

Very similar to taking a probiotic or prebiotic to maintain a healthy gut, one can imagine the development of a similar idea for the airway microbiota where one inhales certain types of healthy bacteria (probiotics) with the addition of a prebiotic, which is the bacteria’s food and means for healthy growth.

We look forward to contributing further to this area and helping people live healthier and happier lives.

For further information, the article is Open Access at:

http://www.cell.com/trends/microbiology/abstract/S0966-842X(15)00059-1