Oral Probiotic Administration to Modulate the Airway Microbiome in Obese Asthmatic Subjects

Obesity is a major health concern in the Deep South resulting in a growing number of metabolic disorders that strain the resources of our healthcare system. Obesity is recognized as a major risk factor for asthma. The Centers for Disease Control and Prevention (CDC) has stated "obesity is associated significantly with the development of asthma, worsening asthma symptoms, and poor asthma control. This leads to increased medication use and hospitalizations." Variations in the airway microbiome are correlated with the risk for development of asthma, and populations of different bacteria vary by phenotype amongst severe asthmatics . Proteobacteria are found in greater proportion in asthmatic subjects relative to healthy controls (37% vs 15%) while non-asthmatic subjects have a relative abundance of Firmicutes (47% vs 63%) and Actinobacteria (10% vs 14%) compared to those with asthma . Amongst those with asthma, obese asthmatic subjects have a relative abundance of Bacteroides (54%) and Firmicutes (26%). Notably, both phyla are part of the gastrointestinal microbiome, suggesting inoculation through gastroesophageal reflux which may be more common in obese individuals. Asthmatics identified as having improvement in their asthma control following treatment with inhaled corticosteroids appear to have a greater relative abundance of Actinobacteria (79.8%) in their airways relative to other asthmatics. Actinobacteria have been associated with the production of anti-inflammatory proteins and are speculated to be involved in increasing steroid responsiveness. Other studies have demonstrated that oral administration of probiotics, including Bifidobacterium species within the phyla Actinobacteria, lead to reduced Th2 cytokine production and eosinophilic inflammation, along with promotion of Regulatory T-cell (Treg) populations within the airway. We hypothesize that administration of over the counter oral probiotics containing Actinobacteria (Bifidobacterium) to obese asthmatic subjects will result in decreased airway inflammation and better asthma control by immune modulation.

Patients enrolled will receive probiotic supplementation following the first bronchoscopy for four weeks. A second bronchoscopy will be performed following probiotic administration.

• This is a proof of concept study to demonstrate that oral probiotic use can modulate the airway microbiome. After informed consent has been obtained, this study will consist of 2 visits over a four week time period. Each visit will include a blood draw (30ml) and a research bronchoscopy/ bronchoalveolar lavage (BAL) (200ml) visit . A urine pregnancy test will be done on all females of childbearing potential prior to the first BAL as well as a CBC, BMP, and blood clotting tests in all participants. Following the first BAL, subjects will be asked to take an over the counter probiotic supplement (Seeking Health Probiota Bifido) nightly which will be provided to the participant by the study coordinator until the 2nd BAL is performed 4 weeks after the first BAL.

The relative abundance of bacterial species in the airways of participants will be quantified from samples obtained during bronchoscopy and compared at baseline and after using oral probiotic supplements daily.

Inclusion Criteria: Moderate to severe asthma requiring medium to high dose inhaled corticosteroids Patients will be recruited through the UAB Asthma Clinic and using the UAB Asthma Clinic Database for the Biospecimen Repository Patients must show spirometry with positive bronchodilator reversibility or have a positive Methacholine Challenge Test within 3 years of enrollment Obesity as defined as BMI over 30 Self-reported or radiographic evidence of gastroesophageal reflux disease Ability and willingness to provide informed consent Exclusion Criteria: Inability of the subject to provide informed consent Inability of the subject to undergo bronchoscopy Use of monoclonal antibody within three months prior to enrollment Use of immunosuppressive medication Use of oral corticosteroids or antibiotics 4 weeks prior to enrollment Use of anticoagulants (warfarin/Coumadin and heparin products). Use of aspirin and/or other non-steroidal anti-inflammatory drugs or clopidogrel (Plavix) within 5 days of bronchoscopy. Pregnancy Diagnosis of HIV, active cancer, or liver disease

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