The problem is to provide lactic acid bacteria having high natural immunity activation ability as well as a natural immunity-activating agent and infection preventative/therapeutic containing said lactic acid bacteria or elements derived from said lactic acid bacteria, and a food/beverage containing these. The problem is solved by lactic acid bacteria belonging to the genus Lactobacillus that are accession number NITE BP-02005 of the NITE NPMD, lactic acid bacteria having natural immunity activation ability that are these lactic acid bacteria or naturally or artificially mutated lactic acid bacteria thereof, lactic acid bacteria having a base sequence of the 16S rDNA region shown by SEQ ID NO: 1, a natural immunity-activating agent having as an active ingredient these lactic acid bacteria, dead cells of these lactic acid bacteria, or a treatment product of these lactic acid bacteria, an infection preventative/therapeutic containing as an active ingredient a peptide glycan of these lactic acid bacteria, and a food/beverage containing these.
