The study is designed as a single site, randomized, quadruple-masked, placebo-controlled, parallel group clinical trial. The investigators will screen 343 subjects, with an objective to enroll 144 high risk infants with the PAI-1 risk genotype, who are born between January 1 and May 15, will be randomized (July 15th- August 15th) to one of two treatment groups through the viral season (August 15th to March 15th in 3 yearly cohorts. The treatment groups will be either oral isoflavone supplement (at doses similar to that seen in soy formula) or a matching placebo. Screening will occur January through July of each year, with genotyping occurring at the first visit, and assumption of care of individuals with the risk genotype after randomization. There will be a study run in period until the second week of July at which time subjects will be randomized. At randomization, the investigators will assume the care of the children for all wheezing illnesses. The subjects will have either virtual or in person visits for each of the next 6 visits, followed by an in-person visit at the end of treatment. The subjects will also come in for in-person visits at times of viral illnesses. At randomization, end of treatment, viral illness, and end of study the subjects will have nasal swabs and nasosorption carried out. Blood draws will occur at randomization, end of treatment, and the end of study visit. Stool will be collected for microbiome assessment at randomization, the 3rd or 4th month of treatment, the end of treatment, and the end of the study at the end of the observation year. The study will also measure infant pulmonary function using a wearable device to assess expiratory variability overnight. This will be measured at randomization, viral illness, end of treatment, and at the end of the study after the 1 year observation period. The treatment period will run from August to March 15th for each participant, with a 1 year observation period after this. The study will recruit over 3 consecutive years.
The goal of this clinical trial is to compare soy isoflavones to placebo in children who at risk of asthma and have a genetic variation which results in them making more of a pro-inflammatory protein, plasminogen activator inhibitor-1. The main questions this trail seeks to answer is: will soy isoflavones decrease wheezing episodes in these children when given in the first year of life. Participants will be asked to ingest soy isoflavone or placebo twice daily mixed into a liquid or puree vehicle for 7 months from randomization. There will be 3 mandatory in-person visits, and 6 virtual visits in the first year. There will also be 11 monthly questionnaires and 1 in person visit in the observation year. Participants will have 4 nasal swabs, 3 blood draws, and also provide 4 stool samples over the course of the study.