Microbiome in Chronic Obstructive Pulmonary Disease: Role of Natural Products Against Microbial Pathogens

The "microbiome" is the operative term to refer to a collection of all taxa constituting microbial communities, such as bacteria, archaea, fungi and protists (originally microbiota). The microbiome consists of the indigenous microbial communities and of the host environment that they inhabit. Actually, it has been shown that there is a close relationship between the microbiome and the human health and disease condition. Although, initially, lung was considered sterile, actually, the existence of a healthy lung microbiome is usually accepted. Lung microbiome changes are reported in chronic obstructive pulmonary disease (COPD) and in its exacerbation. Viral and bacterial infections of the respiratory system are a major cause of COPD exacerbations (AECOPD) leading increased local and systemic inflammation. Detection rates of virus in AECOPD are variable between 25-62% according to detection method. Study of human airway and lung disease virome are quite recent and still very limited. The purpose of this review is to summarize recent findings on the lung microbiome composition with a special emphasis to virome in the COPD and in AECOPD. Some drugs of natural origins active against resistant bacteria and virus are described.