Provided is a method of producing a culture product of a microorganism, for obtaining a culture product excellent in anti-inflammatory property in which a ratio between the production amounts of IL-10 and IL-12 (ratio of IL-10/IL-12) is large. Specifically, provided is a method of producing a culture product of Lactobacillus plantarum, including culturing Lactobacillus plantarum using a medium containing an unsaturated fatty acid ester until a time point at or before an end of a logarithmic growth phase, to thereby obtain a culture product of Lactobacillus plantarum. The unsaturated fatty acid ester is an ester formed through a reaction between a monovalent or polyvalent unsaturated fatty acid and a polyhydric alcohol, or a derivative of the ester. A preferred example of the unsaturated fatty acid ester is a monooleic acid ester. FIG 1