Methods: BALB/c mice were intranasally (i.n.) sensitized with PBS in presence or absence of 1µg HDM and challenged i.n. with PBS or 10µg HDM on days 7 till 11 while being fed a diet containing 0, 1 or 2.5 w/w% GOS. On day 7, 9, 11, and 13 budesonide was either or not instilled oropharyngeally. On day 14, airway resistance to metacholine and inflammation were determined. Leukocyte subtypes were analyzed in the broncho-alveolar lavage (BAL) and in lung cell suspensions. Mucosal mast cell protease-1 (mmcp-1) was measured in serum and cytokines in lung homogenates.
Results: HDM-allergy significantly increased airway responsiveness and BAL leukocyte numbers. Budesonide treatment suppressed this, which reached significance in mice fed GOS. Budesonide reduced the number of lymphocytes and eosinophils in the BAL. Feeding GOS in absence of budesonide treatment reduced the number of eosinophils as well. In addition, both GOS as well as budesonide reduced mmcp-1 serum concentrations. Interestingly, only in the GOS fed mice, budesonide treatment reduced IL-33 and IL-13 concentrations and the frequency of Th2 cells in the lung.
Conclusions: Dietary intervention using GOS may be a novel way to improve effectiveness of anti-inflammatory drug therapy in asthma.
This study was performed within the framework of Carbohydrate Competence Center (WP25).