Dietary intervention to reduce exacerbation in children with asthma

Asthma is the most prevalent chronic disease in children. Patients with asthma are more susceptible to a wide range of common viral respiratory infections; however, the effect of asthma on immune responses to viral and bacterial stimulants in children is poorly understood. Our aims were to examine the differences in cytokine responses of peripheral blood mononuclear cells (PBMCs) as well as PBMC composition in children (3-11 years) with and without asthma. Next, we wanted to determine whether a high fruit and vegetables (F&V) diet can enhance innate immune responses of PBMCs in asthmatic children with a history of exacerbations and low F&V intake (≤3 serves). Children with asthma demonstrated a deficient interferon (IFN)-γ respond to both rhinovirus (RV)-1B and lipopolysaccharide (LPS) infection compared with healthy age-matched controls. RV1B-induced IL-1β response was also higher in asthmatics than controls. In contrast, both IL-1β and IL-6 were significantly lower in response to house dust mite (HDM) and LPS in children with asthma compared to controls. We also showed that the frequency of innate lymphoid cell (ILC) 1, ILC2, and ILC3 was significantly higher in children with asthma compared to controls. The high F&V intervention increased LPS-induced IFN-γ and IFN-λ production after 3months, compared to baseline. Additionally, correlation analysis showed that RV1B-induced IFN-λ production by PBMCs was positively associated with change in plasma lycopene at 6 months. In summary, our findings indicate that children with asthma have impaired innate immune responses. We have also observed the beneficial effects of plasma total and individual carotenoids on in vitro cytokine production by PBMCs. A high F&V diet may be an effective strategy for improving innate immune responses in children with asthma.