The Effect of Chlorhexidine on the Oral and Lung Microbiota in Chronic Obstructive Pulmonary Disease

Inclusion Criteria

• Willingness to undergo sputum induction
• Capability to provide written informed consent
• Age ≥ 40 years and ≤ 85 years
• FEV1/FVC ratio (post bronchodilator) ≤70%
• FEV1 (post bronchodilator) ≤ 65%
• Presence or high likelihood of chronic cough and sputum production defined as one of the following:

Presence of chronic cough and sputum will be defined by responses to the first two questions on the SGRQ. Subjects who respond positively to both question 1 (cough) and question 2 (sputum) on the SGRQ as either "several days per week" or "almost every day" will be eligible.

COPD exacerbation within the previous 12 months defined as taking antibiotics and/or prednisone for respiratory symptoms, hospitalization or emergency department visit for respiratory illness.

• Current or former smoker with lifetime cigarette consumption of > 10 pack-years
• Negative serum pregnancy test at the baseline visit if patient is a pre-menopausal female (menopause defined as absence of a menstrual cycle in the last 12 months)
• Must be fluent in speaking the English language
• Have a minimum of four teeth

Exclusion Criteria

• Not fully recovered for at least 30 days from a COPD exacerbation.
• Treated with antibiotics in the last 2 months.
• The presence of dentures (full plate).
• Active oral infection being treated by health care professional.
• Current use of chlorhexidine or over-the-counter mouth washes in the last 2 months.
• Known allergy or sensitivity to chlorhexidine
• Unstable cardiac disease
• Clinical diagnosis of asthma, bronchiectasis, cystic fibrosis, or severe alpha-1 antitrypsin deficiency
• Active lung cancer or history of lung cancer if it has been less than 2 years since lung resection or other treatment. If history of lung cancer, must have no evidence of recurrence in the 2 years preceding the baseline visit.