Inclusion Criteria:

• 1. Outpatient adults of either sex 18-65 years of age.
• 2. Subjects with body mass index (BMI) ≥ 30 kg/m2.
• 3. Physician diagnosis of asthma.
• 4. Documented history of either bronchodilator reversibility or positive methacholine challenge in past 2 years:
• i. Reversibility of at least 12% increase in forced expiratory volume in 1 sec (FEV1) 15-30 minutes after inhaling 2-4 puffs of albuterol or ii. Positive methacholine challenge defined as a 20% fall in FEV1 compared to baseline at less than 16 mg/ml.
• 5. Negative urine pregnancy test in women of childbearing potential\* (confirmed during screening).
• 6. Regular treatment with inhaled corticosteroid (ICS) and long-acting beta agonist (LABA) combination medication for at least 3 months; on a stable dose for the 4 weeks prior to Visit 1
• 7. Subjects with a smoking history \<10 pack years and no smoking in the last year.
• 8. Willing and able to give informed consent and adhere to visit/protocol schedules.
• Allergic Asthma Subjects
• 1. Subjects with serum IgE \>100 IU/ml and
• 2. Positive skin prick test
• 3. Absolute eosinophil count \>150/uL or FeNO \>30 ppb (if on systemic steroid therapy)
• Non-allergic Asthma Subjects
• 1. Subjects with serum IgE \<100 IU/ml and/or
• 2. Negative skin prick test
• 3. Absolute eosinophil count \< 150/uL

Exclusion Criteria:

• 1. Children \< 18 years of age.
• 2. Subjects with body mass index (BMI) \< 30 kg/m2.
• 3. Pregnancy
• 4. Lung disease other than asthma including chronic obstructive pulmonary disease (COPD) or emphysema, bronchiectasis, sarcoidosis, or interstitial lung fibrosis.
• 5. Smoking history \> 10 pack years or any cigarette use within the previous twelve months.
• 6. Upper or lower respiratory tract infection within one month of the study.
• 7. Positive COVID-19 test in last 3 months.
• 8. Untreated or uncontrolled sleep apnea.
• 9. Recent active substance abuse (last 6 months).
• 10. Current use of dupilumab or other biologic therapy for asthma
• 11. Near fatal asthma (intubation or intensive care unit (ICU) admission for asthma) within past 1 year.
• 12. Other major chronic illness in the opinion of the investigator that might interfere with the study; including, but not limited to, uncontrolled diabetes, uncontrolled HIV infection or other immune system disorder, seizure disorders, renal failure, liver disease, or unstable psychiatric illness.
• 13. Participation in an intervention study (including non-pharmacologic interventions) or use of investigative drugs within the past 30 days or plans to enroll in such a trial during the study.