Your lung microbiome & respiratory health
Uninvited bugs in your lungs
You may be aware that having a balance of good bacteria and a healthy microbiome in your gut plays an important role in your digestive, immune and respiratory health (and other body systems). What is less known, is that like the intestine, your lungs also have a microbiome.
Your lungs are full of microorganisms. The good guys provide protection from harmful microorganisms, whilst the bad guys are undesirable intruders which can cause problems if their numbers overwhelm your immune system.
It has now been shown that it’s not only the composition of your gut microbiota that can play a role in the severity of asthma via the gut-lung axis, but also the composition of your lung microbiota. Recent research has revealed that there are differences between the lung microbiomes of healthy people and those with asthma.
Comparison of asthmatic individuals to those with no respiratory disease has shown that many of those with asthma have a higher proportion of potentially harmful bacteria in their lungs and reduced beneficial bacteria.
In healthy people, the lung microbiota is characterized by the prevalence of bacteria belonging to the group of Bacteroidetes (mostly Prevotella and Veilonella spp), whilst in asthmatics it’s the Proteobacteria group which is predominant (mostly Haemophilus, Moraxella and Neisseria spp). The presence of proteobacteria has been linked to bronchial hyper-reactivity and asthma severity.
In asthma the lung microbiome composition changes due to a disruption of the delicate balance between the immigration and elimination of bacteria.
3 Main factors that influence the lung microbiome include:
1. Different organisms moving into the airways as we breathe, from our stomachs or our mouths.
2. How effectively the lungs can remove microbes.
3. The conditions in the lung and how favourable they are to microbial growth.
Your lung microbiome interacts with your immune system, thus influencing inflammation. For example, early infections with viruses may alter lung microbiome composition favouring the emergence of Proteobacteria, which as we have seen, is linked to inflammation in asthma.
Interactions between your airway microbiome, your immune responses and potential environmental exposures are thought to influence the type and degree of airway inflammation. In 2015 research published in The Lancet revealed that exacerbations of asthma (and other chronic lung diseases) can be linked to a disruption in the microbiome of the patient’s lungs (lung dysbiosis).
The researchers found that bacterial communities in the airways of a person with a chronic lung disorder airways are disordered, creating inflammation, which in turn further disorders the bacterial communities. This cycle of dysbiosis and inflammation is common across a number of chronic inflammatory lung diseases.
So how can we enhance the microbiome of our lungs?
Emerging studies are showing that the direct manipulation of the airway microbiome, particularly in early life, may help to prevent or treat asthma, however this is a fairly new area of research.
Whilst interventions on the lung microbiome are only very recent, the use of probiotics and prebiotics in modulating the gut microbiome is well established in helping to enhance your immune health and your tolerance to allergenic substances.
Animal studies have also shown that supplementing with probiotic strains Lactobacillus reuteri, LGG, and Bifidobacterium breve decrease airway hyper-responsiveness and the inflammation of lung tissue.
Therefore, getting your gut in as good shape as possible with an intake of prebiotic and probiotic rich foods, or if necessary with supplementation, not only enhances your gut and immune health, but can also play a role in reducing inflammation in your lungs.
References:
Chung, KF. Airway microbial dysbiosis in asthmatic patients: A target for prevention and treatment? The Journal of Allergy and Clinical Immunology, 2017;139(4):1071-1081.
Chung KF. Potential Role of the Lung Microbiome in Shaping Asthma Phenotypes. Annals of the American Thoracic Society. 2017;14(Supplement_5): S326-S331.
Cicco, MD, Pistello, M, Jacinto, T, et al. Does lung microbiome play a causal or casual role in asthma? Pediatric Pulmonology. 2018; 53(10):1340-1345
Feleszko W, Jaworska J, Rha RD, et al. Probiotic-induced suppression of allergic sensitization and airway inflammation is associated with an increase of T regulatory-dependent mechanisms in a murine model of asthma. Clinical and Experimental Allergy. 2007;37(4):498–505.
Huang, YJ. The respiratory microbiome and innate immunity in asthma. Current Opinion in Pulmonary Medicine 2015; 21(1):27-32
Hougee S, Vriesema AJM, Wijering SC, et al. Oral treatment with probiotics reduces allergic symptoms in ovalbumin-sensitized mice: a bacterial strain comparative study. International Archives of Allergy and Immunology. 2010;151(2):107–117.