PROBLEM TO BE SOLVED: To provide an antibacterial agent for oral cavity and an antimicrobial composition for oral cavity, the agent and composition having strong antibacterial activity against bad breath-producing bacteria, being sufficiently safe for everyday use, and comprising an antimicrobial component selectively showing strong antibacterial activity against bad breath-producing bacteria without throwing off the balance of flora in the oral cavity to overcome the situation that even healthy people routinely cause dirty oral cavity and a decrease in salivary secretion, which tend to cause bad breath due to an increase in bad breath-producing bacteria.SOLUTION: According to the present invention, there is provided an oral composition comprising thymohydroquinone or thymoquinone, which has strong antibacterial activity against bad breath-producing bacteria, or an extract, compressed oil, or essential oil of black cumin, Eupatorium japonicum, Smilax glabra, horsemint, thyme, etc., which contain any of them.SELECTED DRAWING: None【課題】健常人でも日常、口腔内の汚れ、唾液分泌の低下により、口臭産生菌が増加し口臭が発生しやすい状況になるため、口臭産生菌に対して強い抗菌活性を有し、日常使用するのに十分に安全であり、かつ口腔内フローラのバランスを崩さずに口臭産生菌に対して選択的に強い抗菌活性を示す抗菌成分を含む口腔用抗菌剤および口腔用抗菌組成物を開発すること。【解決手段】口臭産生菌に対する強い抗菌活性を有するチモヒドロキノン、チモキノンやそれらを含有するブラッククミン、フジバカマ、ケナシサルトリイバラ、ホースミント、タイム等の抽出物、圧搾油、又は精油により選択的に口臭産生菌を殺菌または口臭の発生を抑制する口腔組成物。【選択図】なし
