A bacterial extract of OM-85 Broncho-Vaxom suppresses ovalbumin-induced airway inflammation and remodeling in a mouse chronic allergic asthma model

Chronic allergic asthma is characterized by Th2-polarized inflammation, airway remodeling and fibrosis. Broncho-Vaxom (OM-85 BV) is an extract of eight different bacterial species, which has been used for airway infections in humans. However, the effects of microbial products on the prevention of chronic asthma remain unclear. In this study, we attempt to determine whether OM-85 BV inhibits chronic inflammation and airway remodeling in the ovalbumin (OVA)-induced mouse allergic asthma model. The oral administration of OM-85 BV before the sensitization markedly alleviated the OVA-induced airway hyperresponsiveness (AHR) and inhibited inflammatory cell infiltration, mucus hypersecretion and peribronchial collagen deposition compared with the model group. In addition, OM-85 BV reduced OVA-specific IgE levels in serum and decreased the level of Th2 cytokines in bronchoalveolar lavage fluid (BALF). All these findings in a murine model provide a new way for the immunoregulatory role of OM-85 BV to control the chronic asthma.