PROBLEM TO BE SOLVED: To provide an antibacterial agent which inhibits the proliferation of Streptococcus mutans and Streptococcus sobrinus regarded as bacteria to cause a carious tooth (dental caries) of an oral disease, Actinomyces viscosus, Porphyromonas gingivalis, and Fusobacterium nucleatum regarded as bacteria to cause periodontal diseases, Streptococcus pyogenes of a hemolytic streptococcus of a bacterium to cause inflammation, a Staphylococcus aureus of a bacterium to cause food poisoning and the like, and an oral composition and food and drink contain the same.SOLUTION: The antibacterial agent includes a water and/or organic solvent extract of one or more Ascomycetes or Basidiomycetes selected from the group consisting of Hercium erinaceum (Bull.:Fr.) Pers., Morchella esculenta, Auricularia auricula-judae, Lyophyllum decastes, Pholiota nameko, Poria cocos, Pleurotus pulmonarius (Fr.) Quel., Sparassis crispa (Wulf.) Fr. and the like as an active ingredient, and the oral composition and the food and drink contain the same.
