Take a deep breath – your lung microbiome will appreciate it

There was a time when our reaction to bacteria might have been to ‘eradicate at all costs’. These days we understand that our bodies, particularly our digestive systems, contain large quantities of microbes that play an important role in the performance of many basic functions necessary for life.

These bacteria in our bodies produce chemicals that help us harness energy for our metabolism and nutrients from our food.  They make essential vitamins and act as a first line of defence against potential disease-causing germs. While you might not think of it as such, the microbiome – as these microorganisms are collectively called – could be considered a ‘super organ’ working in harmony with the human body.

The benefits of ‘friendly’ gut bacteria are widely accepted however many of us may not be aware that our lungs also contain their own ecosystem of microorganisms; an ecosystem that scientists are discovering might be just as important to our health and our immune system.

With a 40 year history of respiratory disease research, our scientists are working to advance our knowledge of the lung microbiome. Our aim is to shed new light on the microbial community to see if it can help us develop new medicines.

“Until as recently as 2012, there was little investigation of the lung microbiome” says Dr Jim Brown, who coordinates microbiome research at GSK. “This may have been because it was widely believed by clinicians that the healthy lung was a sterile environment, free from bacteria and other microbes. But research in this area is moving quickly. Now, mapping the lung microbiome is a major goal for scientists investigating new treatment approaches.”

To achieve this, we have joined forces with researchers from the University of Leicester to study changes in the bacterial ecology in the lungs of people with chronic obstructive pulmonary disease (COPD).

COPD is a condition where the airways become inflamed and the air sacs in the lungs are damaged. When people with COPD experience exacerbations – a worsening of symptoms that can be fatal if not treated immediately - we know that bacteria are a major cause.

Our research is investigating how changes in the different bacterial groups in the lung can affect the frequency and severity of exacerbation episodes. We’re also looking at how different treatments affect the different microbial groups and whether they might be potential targets for new medicines.

“As we’ve learned more about COPD over the years and its effect on patients, we’ve come to understand that not all COPD exacerbations are the same” explains Dr Ruth Tal-Singer, Vice-President and Head of COPD Clinical Discovery at GSK. “By looking at the lung microbiome in great detail we’re able to better understand and categorize these episodes. This has implications for how we develop new medicines and how we could better manage patients’ conditions.”

Our research, which has been published in the European Respiratory Journal, uncovered complex patterns of interacting relationships within a diverse population of different species of bacteria in the lung. The research revealed how the fine balance of our lungs’ microbial community may be dictated by only a few bacterial groups.

A key finding was that microbial diversity was reduced during exacerbations, suggesting that having a diverse lung microbiome could act as an additional line of defence in fending off infections and protecting against tissue damage.  Researchers also found that the different types of treatments currently used by COPD patients, such as steroids and antibiotics, can affect the composition of bacteria in the lung. Understanding more about the more dominant species of bacteria in the lung could help us to identify new targets in the body when we’re developing future treatments.

“Looking at the way different microbes in the lung behave showed us that disturbing the composition of just a few of these bacterial groups may greatly impact the overall microbial community structure,” says Dr Zhang Wang, a GSK post-doctoral fellow and lead author of the paper. “The data gave us valuable insights into the relationships between microbes in the lung, the inflammation that can occur as a result and how this can affect a patient’s condition.”

More studies are already underway to confirm these findings in other groups of COPD patients. Together, these will allow us to better characterise different COPD patient groups according to the behaviour and balance of their lung microbiome. Our ultimate goal is to harness the power of the lung microbiome to develop new medicines for patients.