RT Journal Article SR Electronic T1 The lung microbiome in health and disease JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 525 OP 529 DO 10.7861/clinmedicine.17-6-525 VO 17 IS 6 A1 Miriam F Moffatt A1 William OCM Cookson YR 2017 UL http://www.rcpjournals.org/content/17/6/525.abstract AB The Human Microbiome Project began 10 years ago, leading to a significant growth in understanding of the role the human microbiome plays in health and disease. In this article, we explain with an emphasis on the lung, the origins of microbiome research. We discuss how 16S rRNA gene sequencing became the first major molecular tool to examine the bacterial communities present within the human body. We highlight the pitfalls of molecular-based studies, such as false findings resulting from contamination, and the limitations of 16S rRNA gene sequencing. Knowledge about the lung microbiome has evolved from initial scepticism to the realisation that it might have a significant influence on many illnesses. We also discuss the lung microbiome in the context of disease by giving examples of important respiratory conditions. In addition, we draw attention to the challenges for metagenomic studies of respiratory samples and the importance of systematic bacterial isolation to enable host–microbiome interactions to be understood. We conclude by discussing how knowledge of the lung microbiome impacts current clinical diagnostics.