Disclosed are a method for screening a food which enables the production of a milk having an immunomodulating effect, a novel food having an immunomodulating effect, and a method for producing the same. A feed or a substance, which enables the production of a breast milk having an immunomodulating effect, is screened by identifying a feed or a substance capable of increasing or decreasing the amount of microRNA(s) contained in the milk of a mammal by using, as an indication, the correlation between the microRNA profile of the milk and a feed taken by the mammal or a substance contained in the feed.
