Table 2.

Bacterial composition of the “healthy” airways.

Microbiome	Predominant Members	References
Nasal	Phyla: Actinobacteria, (principally families Corynebacteriaceae and Propionibacteriaceae), Bacteroidetes, Firmicutes, Proteobacteria Genera: Bifidobacterium, Corynebacterium, Staphylococcus, Streptococcus, Dolosigranulum, Moraxella	(Lemon et al., 2010; Bassis et al., 2014; de Steenhuijsen Piters et al., 2015; Mammen and Sethi, 2016; Kumpitsch et al., 2019; Dimitri-Pinheiro et al., 2020)
Oral	Phyla: Actinobacteria (families Actinomycetaceae and Micrococcaceae), Bacteroidetes, Chlamydiae, Chloroflexi, Firmicutes, Fusobacteria, Gracilibacteria (formerly GN02), Proteobacteria, Spirochaetes, SR1 (candidate phylum Absconditabacteria), Synergistetes, Saccharibacteria (formerly TM7) Genera (selected representatives): Actinomyces, Campylobacter, Corynebacteria, Fusobacterium,Haemophilus, Lactobacillus Moraxella, Neisseria, Prevotella, Rothia, Veillonella, Streptococcus	(Bassis et al., 2014; McLean, 2014; Ramakrishnan et al., 2016; Huffnagle et al., 2017; Sharma et al., 2018; Sultan et al., 2018; Deo and Deshmukh, 2019)
Lung	Phyla: Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria Genera: Fusobacterium, Haemophilus, Neisseria, Prevotella, Streptococcus, Veillonella	(Tunney et al., 2008; Hilty et al., 2010; Charlson et al., 2011; Fodor et al., 2012; Segal et al., 2013; Einarsson et al., 2016; Moffatt and Cookson, 2017; Mendez et al., 2019)