Introduction: Prior work examines age-associated change to the human microbiome however dedicated study of the respiratory microbiome is lacking. Aim: To assess the respiratory microbiome in ‘genetically linked’ pairs of young and elderly participants to examine age-associated change. Methods: N=48 Singaporean subjects were recruited from the Exercise for LIFE Across Asia (ELIXA) cohort as 24 ‘pairs’: a young ( 60yo). In addition to sputum sampling for targeted 16S rRNA gene amplicon sequencing, subjects undertook clinical and lung function assessment. Results: Unpaired analysis of young and elderly ‘pairs’ reveal broadly comparable respiratory microbiome profiles with Streptococcus, Prevotella, Neisseria, Rothia and Veillonella representing the top genera. Interestingly, however, paired analysis between young and elderly duos revealed differences at the phyla level with elderly individuals exhibiting higher Firmicutes to Proteobacteria ratios compared to their ‘paired’ younger counterparts (p Conclusion: An increased Firmicute/Proteobacteria ratio, seen in elderly subjects, potentially represents an important age-associated shift in respiratory microbiome architecture whose role in the development of respiratory disease remains to be elucidated. Funding: This work was supported by the Ageing Research Institute for Society and Education (ARISE), Nanyang Technological University, Singapore [ARISE/2017/6].
