Effect of Fasting on the Asthma Inflammasome

Background: Research shows that restricting calories has a positive effect on immune cell health in healthy people. Researchers want to learn if it will help people with asthma. They want to better understand how the body s immune response and lung function responds to short-term calorie restriction. For this, they want people to fast (no food or drink except water) for 24 hours. Objective: To explore the benefits of calorie restriction in people with asthma. Eligibility: Healthy people ages 18 to 60 who have a history consistent with asthma and prior documentation of airflow obstruction or wheezing. Design: * Participants who have taken part in asthma research at NIH will be screened with a telephone interview. All other participants will have a medical history, blood tests, and physical exam. * Eligible participants will return to the NIH Clinical Center one morning for 2 hours. They will be fed breakfast. They may have blood and urine tests. * Participants will then fast for 24 hours. * Participants will return to the Clinical Center the next morning for 4 hours. They will have blood drawn. They will eat breakfast and then repeat blood draws 2.5 hours later. They will have a urine test. * Blood and urine tests will be done at the end of the fast and after the meals to confirm that the participant fasted for the full 24-hour period. * Participants will have lung function tests and exhaled gas measurements. A machine will measure the volume of air they can breathe out. Some gases in the breath increase with inflammation. Participants will breathe into a machine that analyzes the gases in their breath.