Lung and Gut Microbiome in Chronic Obstructive Pulmonary Disease

Study Overview
=================
Brief Summary
-----------------
Increasing evidence have implied that microbiota from airway and gut might be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the cross-talk between respiratory and gastrointestinal microbiome in COPD is still undetermined. The study is aimed to investigate the interaction between lung and gut flora, and their role in the process of COPD.

Detailed Description
-----------------
Despite the high prevalence of chronic obstructive pulmonary disease (COPD), there continues to be a large gap in our understanding of disease pathogenesis and mechanisms accounting for large variability in disease phenotype. Cigarette smoking is the principal cause of COPD, but only approximately 15% of adults with substantial tobacco exposure develop clinical COPD. Besides, bacterial colonization or infection is also considered as an important factor in COPD. There are very limited data from microbiome studies that suggest that respiratory and gastrointestinal microbiota may be involved in the pathogenesis of COPD. However, the cross-talk between between lung and gut microbiome, and their relationship with various clinical phenotypes of COPD. Here, we conducted 16S rRNA-based pyrosequencing to evaluate the link between the lung-gut axis and the clinical phenotypes of COPD, such as lung function, emphysema, symptoms, exacerbations, inflammation levels and metabolic features.

Official Title
-----------------
The Relationship Between Lung and Gut Microbiome in Chronic Obstructive Pulmonary Disease

Conditions
-----------------
Chronic Obstructive Pulmonary Disease

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: males aged 40-80; diagnosed with COPD according to the GOLD guidelines; clinically stable patients without medication changes or exacerbation in two months; smoking history of more than 10 pack years Exclusion Criteria: diagnosed with unstable cardiovascular diseases, significant renal or hepatic dysfunction or mental incompetence; diagnosed with asthma, active pulmonary tuberculosis, diffuse panbronchiolitis, cystic fibrosis, clinically significant bronchiectasis, exacerbation of COPD or pneumonia in two months; prescribed immunosuppressive medications.

Ages Eligible for Study
-----------------
Minimum Age: 40 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| COPD<br>Smokers with clinically stable chronic obstructive pulmonary disease (COPD) | |
| healthy control<br>Age-matched subjects without chronic obstructive pulmonary disease (COPD) | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microbiota that can predict the progress of lung function | The study is aimed to investigate the relationship between the microbiota and the progress of lung function in COPD | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bacteria related to inflammatory factors | The association between microbiota and inflammatory factors from host is also investigated | 6 months | 
| Bacteria related to metabolomics | The association between microbiota and metabolites from host is also investigated | 6 months |