Dr. Litonjua is interested in the management of asthma patients and how to better prevent asthma exacerbations. As part of this, the use of biologics and specific nutrients hold promise in the treatment of these patients.

Dr. Litonjua's research primarily deals with investigating factors that both increase and decrease the risk of developing asthma, wheezing, and allergic disorders in childhood. As part of this, he has investigated a broad range of prenatal and early life exposures including maternal diet, exposure to allergens, exposure to early life environment (e.g. pets, daycare attendance, air pollution, etc). He co-led a clinical trial of vitamin D supplementation in pregnancy to prevent asthma in the offspring.

He has an interest in identifying genetic and epigenetic marks that affect asthma development and is also working on the interaction between these genetic and epigenetic factors and environmental exposures on the development of asthma and allergies.

Dr. Litonjua has begun to examine the role of the gut microbiome and the environmental microbiome in early life on the development of asthma and allergies in children.