The present invention discloses a novel milk-fermented product comprising a group of peptides. The peptides are composed from no. 1 to no. 7 of the figure that is selected from the group consisting of FIG. 11 to FIG. 18. And the novel milk-fermented product is used for suppressing the reduction of bone mineral density. Therefore, the novel milk-fermented product could be a component of foods, nutrient supplement or medicine for treating or preventing osteoporosis.
