The microbiome in chronic inflammatory airway disease: A threatened species.

The human body is exposed to a multitude of microbes and infectious organisms throughout life. Many of these organisms colonise the skin, gastrointestinal tract (GIT) and airway. We now recognise that this colonisation includes the lower airway, previously thought to be sterile. These colonising organisms play an important role in disease prevention, including an array of chronic inflammatory conditions that are unrelated to infectious diseases. However, new evidence of immune dysregulation suggests that early colonisation, especially of the GITand airway, by pathogenic micro-organisms, has deleterious effects that may contribute to the potential to induce chronic inflammation in young children, which may only express itself in adult life.