A lactic acid bacterium having a high ability to activate natural immunity, an innate immunity activator containing a product / processed product of the lactic acid bacterium or the like as an active ingredient, and an infectious disease preventive / therapeutic drug or a food or drink containing the same are provided, and A prophylactic / therapeutic agent for an infectious disease containing an active ingredient derived from the lactic acid bacterium, and an object of the invention are to provide food and drink fermented with the lactic acid bacterium. Killed bacteria, a product of the lactic acid bacterium, or an innate immunity activator comprising the processed product of the lactic acid bacterium as an active ingredient, wherein the processed product of the lactic acid bacterium is a culture of lactic acid bacterium, a culture supernatant, a concentrate, Innate immunity activator which is a paste, dried product, liquefied product, diluted product, crushed product, sterilized product, or extract from culture, and pathogenic bacteria or virus containing the innate immunity activator For the prevention of infectious diseases against Has solved the problem with an infectious disease preventive / therapeutic drug, which is characterized in that it is for treatment. 高い自然免疫活性化能を有する乳酸菌、該乳酸菌の産生物・処理物等を有効成分とする自然免疫活性化剤や、それを含有する感染症予防・治療薬や飲食品を提供し、また、該乳酸菌に由来する有効成分を含有する感染症予防・治療薬や、該乳酸菌を用いて発酵させた飲食品を提供することを課題とし、ワイセラ・ヘレニカ（Weissella hellenica）に属する乳酸菌、該乳酸菌の死菌、該乳酸菌の産生物、又は、該乳酸菌の処理物を有効成分とする自然免疫活性化剤であって、上記乳酸菌の処理物は、乳酸菌の、培養物、培養上清、濃縮物、ペースト化物、乾燥物、液状化物、希釈物、破砕物、殺菌加工物、又は、培養物からの抽出物である自然免疫活性化剤、並びに、該自然免疫活性化剤を含有し、病原菌又はウイルスに対する感染症の予防用若しくは治療用であることを特徴とする感染症予防・治療薬によって課題を解決した。
