Identification of Microbiome and Metabolome of Bronchiectasis in Chinese Population.

Study Overview
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Brief Summary
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This study aims to investigate the characteristics of gut microbiome and metabolome in non-CF bronchiectasis patients, hoping to explore the underlying mechanisms as well as the influence of gut microbiota composition on bronchiectasis.

Detailed Description
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Non-cystic fibrosis bronchiectasis is a chronic airway disease characterized by irreversible and progressive dilation of the large airways, bronchi and bronchioles, which severely impairs the life quality of patients and increases the social and economic burden. It is also a heterogenous disease affected by multiple factors such as geography and ethnicity. The incidence of bronchiectasis among the Chinese population is about 1.2%, which has clearly been underestimated. However, due to the lack of awareness, the research of bronchiectasis in China is still in its infancy. Colonization and recurrent infection of pathogen is the primary unsolved problem in clinical practice. With the proposition of gut-lung axis theory, the role of gut microbiota in the pathogenesis of respiratory diseases has been gradually revealed. Evidences have shown that gut microbiota regulates respiratory immunity via releasing soluble bacterial components and its metabolites into the circulation, as well as facilitating the migration of immune cells directly to the lung. In the 1980s, a patient after a colectomy has been reported to generate bronchiectasis. The most common clinical manifestation of pulmonary involved IBD patients is also bronchiectasis, suggesting that the gut-lung axis may be involved in the pathogenesis of bronchiectasis. Therefore, clarifying the role and mechanism of gut microbiota in bronchiectasis and its gut microbiome is expected to provide new theoretical basis and ideas for its diagnosis and treatment.

Official Title
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Identification of Microbiome and Metabolome of Bronchiectasis in Chinese Population and Role of the Gut-lung Axis in Chronic Respiratory Infection With Pseudomonas Aeruginosa.

Conditions
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Bronchiectasis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent Regular bowel movement: every 2 days - 3 times/ day The diagnose of bronchiectasis should refer to BTS guideline 2010 Exclusion Criteria: Diagnosis of ABPA Pregnancy or lactation Active smoking or alcohol using within last 6 months HIV infection Previous abdominal or rectal surgery Diagnosis of chronic gastrointestinal disease, heart disease, diabetes, severe renal insufficiency (GFR < 30ml/min) or immunodeficiency Regular use of the following types of medications (> 2 times per week) within last 2 months: opium, loperamide antidiarrheal, systemic antihistaminic, metoclopramide, proton pump inhibitor Poor compliance or inability to cooperate as judged by the doctor
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 |
| --- | --- |
| Bronchiectasis<br>Patient meets diagnose of bronchiectasis refering to BTS guideline 2010 will be included. | |
| Healthy control<br>Healthy volunteers will be included. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gut microbiome and metabolomics of bronchiectasis patients and healthy control. | The microbiome and metabolome results of gut in bronchiectasis patients will be defined from the stool samples using 16S rRNA Miseq sequencing and nontargeted LC-MS-based metabolomics approach. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung microbiome of bronchiectasis patient. | The bronchoalveolar lavage fluid (BALF) specimens will be obtained from admitted patients undergoing bronchoscopy and the lung microbiome of bronchiectasis patients will be defined from the BALF samples using 16S rRNA Miseq sequencing. | 12 months | 
| BSI (Bronchiectasis Severity Index) score | Assessment of the non-cystic fibrosis bronchiectasis severity according to the BSI score at the time of enrollment. BSI score: scale of 0-26, is calculated from the results of age, BMI(body mass index), FEV1% predicted, exacerbations, hospital admissions, airway organisms colonisation, radiological severity etc.) 0-4, 5-8, >9 were separately defined as mild, moderate, severe bronchiectasis, higher score indicates probable higher mortality rate and hospitalisation rate. | 2 months | 
| Lung function | Lung function will be accessed by Pulmonary Function Tests (PFT) and the parameters including FVC ( forced vital capacity), FEV1 (forced the first second of expiratory volume), FEV1% predicted, FEV1/FVC will be documented at the time of enrollment | 12 months | 
| Sputum bacteriological evaluation. | Sputum bacteriological (pseudomonas aeruginosa and other organisms) will be evaluated. | 12 months | 
| Chest high-resolution computed tomography (CT). | Chest high-resolution computed tomography (CT) results in the recent 6 months will be documented. | 12 months | 
| Acute exacerbation | The time of acute exacerbation in the following year will be recorded according to medical information. | 12 months | 
| Hospitalization | The time of hospitalization in the following year will be recorded according to medical information. | 12 months | 
| Duration to the first exacerbation during the one-year follow up. | The duration to the first exacerbation within one year after the sample collection. | 24 months |