In its original phase, this cohort study recruited subjects who were either HIV-positive or HIV-negative healthy controls, to analyze the community structure of the lung microbiome. Original recruitment was planned to occur both at the University of Michigan Medical Center and clinics, and at VA Ann Arbor Healthcare System.

Enrollment for the original cohort is completed, and all current activity of this project is occurring at VA Ann Arbor, where both Veteran subjects and non-Veteran subjects are eligible to participate. This study is currently recruiting only healthy HIV-negative subjects. Participation, described below, involves a research bronchoscopy procedure.

This is a non-interventional cohort study with single time point cross-sectional comparisons and longitudinal analyses, with the primary study aims of: evaluating how the immune deficiency associated with HIV infection influences the lung microbiome and lung function, and evaluating changes in lung microbiota over time. The study also aims to characterize the microbiome of the lower respiratory tract, determine the relationship between the lower respiratory Microbiome and the upper respiratory and gastrointestinal tract microbiomes, evaluate the influence of smoking on the microbiome compared with the influence of smoking on pulmonary function and respiratory systems, and to evaluate how Pneumocystis infection influences HIV-infected and HIV-uninfected individuals.

Inclusion Criteria:

• Negative HIV testing (by ELISA) during initial study visit
• No signs of respiratory infection at enrollment, such as: fever; recent change in quantity of quality of sputum; chest pain; recent change in shortness of breath or exertional activity
• Willing and able to sign the informed consent document
• If female of child-bearing potential, negative pregnancy test during initial study visit

Exclusion Criteria:

• Pregnancy
• Signs or symptoms of respiratory infection at enrollment
• Unwilling or unable to sign the informed consent document
• Unstable heart disease
• Other systemic disease and unlikely to survive at least 2 years
• Mental incompetence
• Participation in another interventional protocol within the last 6 weeks
• Use of antibiotics for a lung infection within the last 4 weeks
• Renal Failure (creatinine >3)
• Child's Class C Cirrhosis

Healthy individuals with no more than mild treated chronic diseases that would not preclude a research bronchoscopy under moderate conscious sedation. Both never-smokers and active smokers are welcome.

deidentified data and biological specimens deposited with NIH BioLNCC