Analysis of the Microbiome in the Healthy Smokers and COPD Patients

Study Overview
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Brief Summary
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This study is to build a microbiome cohort by collecting sputum and fecal samples every few months for three years from healthy smokers and chronic obstructive pulmonary disease (COPD) patients. The aim of this study is to analyze the composition of microbiome of various samples (e.g. sputum, feces) and describe the difference between healthy smokers and COPD patients.

Detailed Description
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After the introduction of the gut-lung axis theory, extensive studies revealed the diversity of microbiomes among healthy smokers and COPD patients form the respiratory samples or lung tissues. In the previous study, distinct difference in composition of microbiome in lung tissue between healthy smokers and COPD patients was reported. This study is to build a microbiome cohort by collecting sputum and fecal samples every few months for three years from healthy smokers and chronic obstructive pulmonary disease (COPD) patients who are being followed up by Asan Medical Center. The aim of this study is to analyze the composition of microbiome of various samples (e.g. sputum, feces) and describe the difference between healthy smokers and COPD patients. This study would help establishing gut-lung axis model in humans.

Official Title
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Analysis of the Microbiome in the Healthy Smokers and COPD Patients

Conditions
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Pulmonary Disease, Chronic Obstructive, Microbiota

Intervention / Treatment
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* Diagnostic Test: Obtain samples from sputum and feces


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with smoking history at least 10 pack-year Patients with persistent airflow limitation that was not fully reversible (e.g. post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) <0.7) Exclusion Criteria: Patients with co-existing illness that would interfere with study results (e.g., malignancy, congestive heart failure, cerebrovascular disorders, chronic renal failure, diabetes with severe complications, or uncontrolled hypertension) Patients with respiratory disease other than obstructive lung disease (e.g., previous pulmonary resection, tuberculosis-destroyed lung, and bronchiectasis)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy smoker<br>Healthy smokers with smoking history at least 10 pack-years and normal spirometry value | Diagnostic Test: Obtain samples from sputum and feces<br>* Samples are obtained from participants. No further intervention is required. Obtained samples will be further analyzed.<br>|
| COPD patient<br>Patients with smoking history at least 10 pack-years and persistent airflow limitation that was not fully reversible (e.g. post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) <0.7) | Diagnostic Test: Obtain samples from sputum and feces<br>* Samples are obtained from participants. No further intervention is required. Obtained samples will be further analyzed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Alpha diversity measured by operational taxonomic unit (OTU) quantitative analysis | DNA is extracted from each sample from each patient by using a DNA Isolation Kit. The 16S universal primers are used for amplification of 16S ribosomal ribonucleic acid (rRNA) genes with polymerase chain reaction (PCR) system. After amplication, sequencing is performed using the GREENGENES database, after which a metagenomic analysis was performed by the MD Healthcare corporation using MDx-Pro software (Ver.1, Seoul, South Korea). Taxonomic assignment of these sequences is carried out with an operational taxonomic unit (OTU) cutoff of 3%. | An average of 3 months | 
| Microbiome composition by metagenomic analysis | The composition of microbiome is presented as bar graph. | An average of 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Biodiversity described by the Shannon diversity index and the Simpson index | The Shannon index and the Simpson index is calculated by using metagenomic data. | An average of 3 months | 
| Biodiversity described by Principal Component Analysis (PCA) | PCA is performed for all 16S rRNA gene reads clustered at a 97% similarity. | An average of 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic obstructive pulmonary disease, Microbiome