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SAW Lung Microbiome Study in Smokers and Never-smokers

Leibniz Association Senate Board of Competition (SAW) Lung Microbiome Study

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03562442
Enrollment
60
Registered
2018-06-19
Start date
2017-03-29
Completion date
2020-03-01
Last updated
2024-04-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Obstructive Pulmonary Disease (COPD), Healthy, Microbial Colonization, Smoking Cessation

Brief summary

The trial aims to analyse changes in the microbiome of the lower airways after smoking cessation. Microbiome analyses (upper airway swabs, bronchoalveolar lavage, transbronchial brushing) are conducted in smokers before and 6 weeks after smoking cessation. Never smokers serve as a control group and undergo the same sampling procedures once.

Detailed description

The trial aims to analyze changes in the microbiome of the lower airways after smoking cessation. Microbiome analyses (upper airway swabs, bronchoalveolar lavage, transbronchial brushing) are conducted in healthy (and willing to quit) smokers before and 6 weeks after smoking cessation. Never smokers serve as a control group and undergo the same sampling procedures once. Demographic and clinical data of the study subjects are obtained, aiming for homogeneous groups. All personal data are encrypted according to the standard operating procedures of the study site. Pharyngeal and deep nasal swabs are taken. To avoid contamination of the lower airways from the oropharynx through the bronchoscope, standardized procedures are established according to the German guidelines for bronchoscopy. Before bronchoscopy, the endoscope is flushed with sterile saline which is analyzed for 16S ribosomal RNA (rRNA) to control for residual contaminating bacterial desoxyribonucleic acid (DNA). A 300ml bronchoalveolar lavage with warm normal saline solution is taken from the middle lobe. Three covered and microbiologically protected bronchial brushings are obtained from the right upper lobe. This sterile brush is sealed in wax and pushed through the wax just before taking the brushing. All samples are immediately frozen and stored at -80°C until further analyses. For cultivations, samples are kept at 4°C and rapidly processed.

Interventions

BEHAVIORALSmoking cessation

Smoking cessation with or without professional / medical support

Sponsors

Research Center Borstel
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE

Intervention model description

Two groups are recruited in parallel (A) Smokers who quit smoking (Visit 1 before cessation, Visit 2 six weeks after cessation) (B) Never-smokers (Visit 1 only)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Cigarette consumption of at least five cigarettes per day * Caucasian ethnicity

Exclusion criteria

* Continous passive smoking exposure * Systemic steroid therapy during the previous month * Chronic lung disease (exception COPD stage Global Initiative on Lung Disease (GOLD) 0/I/II) * Diabetes mellitus * Pregnancy or breast feeding * active tuberculosis (currently or previously) * respiratory infection in the previous month * antibiotic therapy in the previous two months * immunosuppression * malignancy * interstitial lung disease * rheumatic disease with lung manifestation * member of a collaborative group of the project

Design outcomes

Primary

MeasureTime frameDescription
Change in microbiome pattern in smokers after smoking cessation6 WeeksNumber of bacteria genera in the lung identified by 16S rRNA and bacterial culture

Secondary

MeasureTime frameDescription
Smoking cessation rates6 weeksPercentage of sustained smoking cessation
Lung microbiome in never-smokers0 daysNumber of bacteria genera in the lung identified by 16S rRNA and bacterial culture

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026