A lactic acid bacterium having increased immunopotentiating activity with being mixed with no ester compound of polyol and a fatty acid is provided. A method for producing a lactic acid bacterium whose immunopotentiating activity is increased without coexisting with ester compound of polyol and a fatty acid, comprising: contacting a lactic acid bacterial immunopotentiating activity-increasing composition comprising an ester compound of a polyol and a fatty acid as an active ingredient with a lactic acid bacterium having immunopotentiating activity and then washing the lactic acid bacterium to remove the lactic acid bacterial immunopotentiating activity-increasing composition.