The Gut-Lung Axis and Respiratory Illness in Children
The goal of this single-centre observational study conducted at the Royal Hospital for Children in Glasgow, Scotland, is to employ a multi-omics approach to investigate the "gut-lung axis" in health and disease.

Part A is a cross-sectional study design investigating the postulated bidirectional link between the gut and lung microbiomes in children suffering from respiratory or gastrointestinal conditions. Children with no GI or respiratory issues attending for orthopaedic care will be used as a benchmark for a healthy gut-lung axis. The main questions we aim to answer are:

What does a healthy gut-lung axis look like?
Do children with respiratory issues show an altered gut microbiome?
Do children with GI issues show an altered lung microbiome?

Part B is a longitudinal study design, that aims to assess the effects of biologics on the gut-lung axis by comparing the gut and lung microbiomes in children with asthma at two time-points who are indicated to start biologics therapy (Asthma treatment) or will not receive biologics therapy (asthma control).

Participants will provide:

airway samples (to investigate the lung microbiome)
blood samples (to assess inflammatory and metabolic factors which may mediate communication between the two sites) whilst under general anaesthetic for a treatment related to their standard of care
stool samples (to assess gut microbiome)
dietary information (food diary and/or food frequency questionnaire) to assess relationships between diet and the gut-lung axis.
- EligibilityCriteria: 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). - HealthyVolunteers: Accepts Healthy Volunteers - Gender: All - MinimumAge: 0 Years - MaximumAge: 16 Years - StdAgeList: Child - StudyPopulation: Children attending Royal Hospital for Children, Glasgow receiving general anaesthesia for bronchoscopy, endoscopy or orthopaedic procedures. Children attending Royal Hospital for Children for routine procedures with asthma/wheeze. - SamplingMethod: Non-Probability Sample