The Gut-Lung Axis and Respiratory Illness in Children

Inclusion Criteria: * Any infant/child/young person admitted to the RHC, Glasgow for an elective bronchoscopy or GI endoscopy. * Any infant/child attending for an emergency/elective orthopaedic operation without active respiratory or gastrointestinal conditions or receiving treatment for either condition. (Age range birth to 16 years for all groups recruited). * Any child attending respiratory department at RHC who can induce sputum and is having a blood sample taken, with latter part of standard of care. * Any infant/child/young person admitted to RHC for a clinical care appointment with Asthma/wheeze before commencement of biologics therapy (treatment group). * Any child admitted to RHC with asthma/wheeze not indicated for biologic therapy (asthma control group). Exclusion Criteria: * Use of antibiotics by the day of admission or have used antibiotics in the previous month (unless prophylactic antibiotics \> 1 month use). * Any person 17 years old and above. * Any child known to be infected with, or at high risk of having had exposure to HIV, hepatitis B or hepatitis C viruses * . Any child and/or parent/guardian who cannot understand the English language where consent would be unethical. * Any child with Asthma currently receiving Biologics therapy (unless recruited via bronchoscopy route).