Lung microbiome: are the lungs sterile?

The pulmonary microbiome tends to be confused with the pulmonary microbiota, but there are nuances between the 2 concepts. The pulmonary microbiota refers back to the set of microorganisms that occupy the airway. Nevertheless, the microbiome is defined because the set of genes of all these microorganisms. That’s, it’s all of the genetic material that’s present within the microbiota.

Until recently, the lungs were considered sterile organs. Nevertheless, recent studies have found that this will not be so.

In actual fact, the lung microbiome is gaining in importance. The explanation is that it seems to have an influence on quite a few pathologies, reminiscent of cancer or acute respiratory distress syndrome. Due to this fact, in this text, we’ll explain every thing you have to know.

What’s the “Human Microbiome Project”?

Until not so way back, the lungs were considered sterile organs. That’s, there have been no bacteria or other microorganisms inside them under physiological conditions. Nevertheless, after the invention of the gut microbiota, it became clear that this may not be the case.

The Human Microbiome Project, as reported in a publication by Gut Microbiota for Health, was an initiative of the National Institute of Health (NIH). The goal of this project was to discover the microorganisms related to the human species. That’s, all people who interact with the organism.

The explanation is that it’s known that they might be linked each to diseases and to health itself. This project involved a big investment and lasted a complete of 5 years.

The aim was to check how certain alterations within the human microbiome could interfere with health. They began to review, amongst others, the pulmonary and intestinal microbiome.

For instance, it was observed that the intestinal microbiota had a crucial and direct relationship with inflammatory bowel diseases. Hence, aspects reminiscent of weight loss plan and even genetics influence these conditions.

Other more specific research began to emerge from the Human Microbiome Project . Each of them goals to exhibit the association between certain populations of microorganisms in an organ and a particular disease.

How were lung microorganisms discovered?

The Human Microbiome Project was made possible by quite a few scientific advances. Techniques reminiscent of metagenomics and whole genome sequencing were used to characterize the microbial communities.

The invention of the lung microbiome was more delayed. This delay was as a result of the proven fact that there was an inclination to think that the lungs of healthy people were sterile. As well as, there have been certain difficulties in obtaining samples that may very well be analyzed, for the reason that lower airways are usually not easily accessible.

Nevertheless, recent technologies were developed that helped to beat this obstacle. These technologies are based on high-throughput sequencing of the 16S rRNA gene. 16S ribosomal RNA is considered one of the components of prokaryotic cells.

Due to this fact, when this gene is sequenced, the phylogeny of bacteria might be reconstructed. In other words, correct bacterial identification becomes possible. It’s because most bacteria have a really low rate of evolution. That is explained by a study carried out on the Hospital Clínico de San Carlos.

In brief, it was possible to exhibit that there’s a very wide selection of microorganisms within the lungs. All of them contribute to keeping these organs in good condition.

Why is the lung microbiome necessary?

The pulmonary microbiome is of considerable importance. In accordance with a study published in Cellular and Molecular Life Sciences, considered one of its functions is to advertise immune tolerance. In other words, it helps to forestall an uncontrollable inflammatory response.

This prevents lung damage from occurring when in touch with harmless stimuli. The composition of the pulmonary microbiome can also be considered to be a determining think about the event of certain pathologies. For instance, in lung cancer. In actual fact, it not only plays a job in its development, but also can influence the response to treatment.

The identical is true for asthma. It is a chronic inflammatory disease that affects the airways. Due to this fact, the lung microbiome could also be considered one of the triggers or accountable for the attacks.

Nevertheless, the precise underlying mechanism continues to be unknown. Allergies and acute respiratory distress syndrome are also associated.

Relationship between the lung and gut microbiome

The gut microbiome has been studied greater than the lung microbiome. The explanation, as identified in a publication of the Spanish Society of Pneumology and Thoracic Surgery, is that it’s more abundant. It’s also easier to acquire samples.

Nevertheless, the latest research suggests that each microbiomes interact with one another. It seems that each the pulmonary and intestinal microbiomes influence the immune system.

Intestinal microorganisms produce metabolites that exert actions on the pulmonary level. Specifically, they synthesize short-chain fatty acids, reminiscent of acetate and propionate. Each are derived from the digestion or fermentation of dietary fiber.

These fatty acids help regulate the inflammatory response. Inflammation is a process that triggers our immune system as a defense mechanism. Some individuals with lung problems have low levels of those fatty acids.

Something similar happens with a bacterium called Helicobacter pylori. It’s a microorganism present within the digestive system of a really high percentage of the population. The bacterium would have a protective effect in children. Colonized children have less risk of affected by asthma and allergy.

Quite the opposite, when populations of certain bacterial species within the intestine decrease, there may be a greater predisposition to allergy.

The way to maintain a healthy lung microbiome?

Scientists don’t yet know exactly methods to maintain a healthy lung microbiome.

It’s believed that weight loss plan, lifestyle, and exposure to certain agents play a determining role. The gut and lung microbiomes are interrelated, as we now have already discussed, so taking good care of one can also be taking good care of the opposite.

The gut microbiota is greatly influenced by what we eat, by probiotics and prebiotics. Having a weight loss plan that features these elements will help boost the immune system and, in turn, improve the lung microbiome.

It’s also advisable to eat an adequate amount of fiber. Digestion of foods wealthy in soluble fiber promotes the synthesis of short-chain fatty acids.

Why is that this discovery necessary?

Until recently, the lungs were considered a sterile organ. Nevertheless, it’s now known that quite a few microorganisms exist there.

Alteration of bacterial populations is related to different pathologies. For instance, it could influence the event and treatment of lung cancer or asthma. So its importance is transcendental for medicine.

Nevertheless, more research continues to be needed to know exactly how this balance works. The lung microbiome has opened up recent horizons in the chances for the treatment and study of chronic diseases of the respiratory tract.

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