Lactic acid bacteria according to the present invention is configured to enter M cells. The lactic acid bacteria allow galectin-9 to bind thereto by filamentation, and thus, galectin-9 which has passed through and has been expressed in the M cells binds to the filament lactic acid bacteria. Also, lactic acid bacteria (Lactobacillus salivarius AI-001) are provided by allowing filament lactic acid bacteria, to which galectin-9 binds, to bind to IgE antibodies so as to regulate the immunity system.