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 human health
and disease condition. Although, initially, the 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 to increased local and
systemic inflammation. Detection rates of virus in AECOPD are variable between 25-62% according to
the detection method. The study of human airway and lung disease virome is 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 on virome in COPD and in AECOPD. Some drugs of natural origins active
against resistant bacteria and virus are described.
