Dysbiosis of upper respiratory tract microbiota in elderly pneumonia patients

Bacterial pneumonia is a major cause of morbidity and mortality in elderly. We hypothesize that dysbiosis between regular residents of the upper respiratory tract (URT) microbiome, that is balance between commensals and potential pathogens, is involved in pathogen overgrowth and consequently disease. We compared oropharyngeal microbiota of elderly pneumonia patients ( n =100) with healthy elderly ( n =91) by 16S-rRNA-based sequencing and verified our findings in young adult pneumonia patients ( n =27) and young healthy adults ( n =187). Microbiota profiles differed significantly between elderly pneumonia patients and healthy elderly (PERMANOVA, P