The present invention provides a composition for inhibiting proliferation of a bacterium provided with a menaquinone synthesis route via futalosine or a futalosine derivative, which contains a fatty acid having 18 carbon atoms and a hydroxyl group at the 10-position as an active ingredient. Furthermore, the present invention provides a composition for preventing or treating a disease caused by a bacterium provided with a menaquinone synthesis route via futalosine or a futalosine derivative.
