Microbial Colonization Distribution and Adaptive Evolution of Lower Respiratory Tract in Bronchiectasis Patients.

November 17, 2025 updated by: Second Affiliated Hospital, School of Medicine, Zhejiang University

Microbial Colonization Distribution and Adaptive Evolution of Lower Respiratory Tract in Bronchiectasia Patients.

Qualified sputum samples from bronchiectasis patients were collected regularly every month for three consecutive years to analyze the microbiome changes of lower respiratory tract of bronchiectasis patients by metagenomic sequencing. Pseudomonas aeruginosa was isolated and the whole genome was sequenced to analyze the adaptive evolution，including virulence, quorum sensing and drug resistance under host pressure. The aim of the study is to clarify the rule of microflora colonization distribution and adaptive evolution in the lower respiratory tract of patients with bronchiectasis, to predict the acute attack and prognosis of patients with microbiome changes, and to find more new prevention and treatment methods by adjusting the microbiome of the lower respiratory tract.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Bronchiectasis is an abnormal, permanent dilatation of the bronchi, which presents as cough, expectoration and recurrent pulmonary infections. Epidemiological survey researchs have found that the number of bronchiectasis has increased rather than decreased in the last decades. Asia has the highest prevalence of bronchiectasis, with 1,200 cases in every 100,000 people over the age of 40 in China, and this rate can be seriously underestimated due to difficulties in identifying COPD. The mortality rate of bronchiectasis patients is more than twice that of the general population, placing an increasing burden on global health care systems. Chronic infection in bronchiectasis is common and had a big influence on prognosis. Pseudomonas aeruginosa is considered to be the most common colonization bacterium. At present, the mechanism of bronchiectasis and its relationship with lower respiratory tract infection have not been fully elucidated. Therefore, it is important to have an in-depth understanding of the colonization distribution and adaptive evolution of the microbiome in the lower respiratory tract, to predict the acute attack and prognosis with the application of microbiome changes, and to find more new and effective prevention and treatment methods by regulating the microbiome in the lower respiratory tract. Qualified sputum specimens from bronchiectasis patients were collected regularly every month for three consecutive years. Metagenomic sequencing was used to analyze the microbiome changes of lower respiratory tract in these patients. Pseudomonas aeruginosa was isolated and the whole genome was sequenced to analyze the adaptive evolution of its virulence, group sensitivity and drug resistance under host pressure.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
1850

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Zhejiang
      • Hangzhou, Zhejiang, China
        • Recruiting
        • 2ndAffiliated Hospital, School of Medicine, Zhejiang University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 79 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Bronchiectasis patients aged 18 to 79.

Description

Inclusion Criteria:

  • Bronchiectasis patients in clinically stable period;
  • Two or more chest infections in the previous year;
  • Chest CT confirmed bronchiectasis (bronchial to arterial ratio >1).
  • Chronic colonization of pseudomonas aeruginosa and was clinically stable in 6 months prior to the study.

Exclusion Criteria:

  • deterioration of illness (defined as at least 24 hours of three or more of the following symptoms: increased cough, increased sputum volume, purulent sputum, hemoptysis, increased dyspnea, increased wheezing, fever ((≥38°C) or discomfort, the attending physician agrees that antibiotic treatment is required);
  • current smokers, or former smokers who have stopped smoking less than 1 year ago, have a history of more than 15 packets of age, or CT showed as emphysema;
  • cystic fibrosis patients;
  • active allergic bronchopulmonary aspergillosis;
  • active tuberculosis patients;
  • patients with poor asthma control;
  • pregnant or breastfeeding women.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Bronchiectasis patients group
Bronchiectasis patients group: Sputum specimens from bronchiectasis patients aged 18 to 79 years old .
Healthy control group
Healthy control group: Sputum specimens from healthy people.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change from baseline SNP of PA population in sputum samples
Time Frame: once per 3 month for 3 years
To assess the SNP changes of PA population in sputum samples compared with PAO1 wildtype
once per 3 month for 3 years
Species richness and antibiotic suscepibility change from baseline in sputum samples
Time Frame: once per 3 month for 3 years
To assess the species richness and antibiotic suscepibility change from baseline in sputum samples
once per 3 month for 3 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
pulmonary function
Time Frame: once per year for 3 years
To assess the lung functon change
once per year for 3 years
chest CT
Time Frame: once per year for 3 years
To assess the severity of lung lesions
once per year for 3 years
BSI scores
Time Frame: once per year for 3 years
To assess the severity index of bronchiectasis.
once per year for 3 years
E-FACED scores
Time Frame: once per year for 3 years
To assess the severity index of bronchiectasis.
once per year for 3 years
SGRQ questionnaire
Time Frame: once per year for 3 years
To assess the impaired health and quality of life of patients with respiratory diseases
once per year for 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Second Affiliated Hospital, School of Medicine, Zhejiang University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Tongji Hospital
The Affiliated Hospital of Qingdao University
Xuanwu Hospital, Beijing
Beijing Chao Yang Hospital
Zhejiang Provincial People's Hospital
Huadong Hospital
The First Medical Center of Chinese PLA General Hospital
Nanjing Jiangning Hospital
Shandong Public Health Clinical Center
Beijing Chest Hospital, Capital Medical University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 20, 2020

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 7, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 19, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 20, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 17, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2020-066

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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