Respiratory Bacterial Microbiota and Individual Bacterial Variability in Lung Cancer and Bronchiectasis Patients

Respiratory bacterial microbiota plays a key role in human health. Lung cancer microbiome is a significant yet an understudied area while bronchiectasis microbiome is often studied. We assessed the bacterial microbiota in the upper and lower respiratory tract of the patients with lung cancer and bronchiectasis against a healthy group and their variations in individuality. 16S rRNA gene based metagenomic sequencing was used to detect entire bacterial community along with conventional aerobic bacterial culturing. In comparison to healthy, increased bacterial diversity was observed in diseased population. Abundance of more than 1% was considered and bacteria were identified in 97% similarity. Only lung cancer patients exhibited bacteria specific to the disease: Corynebacterium tuberculostearicum and Keratinibaculum paraultunense. However, Enterococcus faecalis and Delftia tsuruhatensis were also observed limited to lung cancer and bronchiectasis respectively, in less than 1% but supported with bacterial culturing. In conclusion the disease condition and intra-group variability should be considered in future with larger cohorts to understand individual patient variability highlighting the social habits and gender of the individual.