Probiotic Potential of <b><i>Lactobacillus</i></b> Species in Allergic Rhinitis

Since conventional allergy medication for asthma or allergic rhinitis (AR) can cause side effects which limit the patients’ quality of life, it is of interest to find other forms of therapy. In particular, probiotic bacteria, such as <i>Lactobacillus</i> species, have shown anti-allergic effects in various mouse and human studies. For instance, administration of some <i>Lactobacillus</i> species resulted in nasal and ocular symptom relief and improvement of quality of life in children and adults suffering from rhinitis. Different changes in cytokine profiles, such as elevated Th1 and decreased Th2 cytokines, reduced allergy-related immunoglobulins and cell immigration have been found in both human and murine studies. Positive effects on patients like less activity limitations or fewer rhinitis episodes and longer periods free from asthma or rhinitis were also described following oral administration of <i>Lactobacillus</i> bacteria. However, it is still unclear how this type of lactic acid bacteria leads to changes in the immune system and thus inhibits the development of allergies or relieves their symptoms. This review gives an overview of current studies and draws conclusions concerning the usage of probiotic <i>Lactobacillus</i> strains in AR.