Our data reveled that Ps-GOS significantly up-regulates the expression of Wnt5a, LRP5, β-catenin, and Fzd4 mRNA, in MC3T3-E1 cells, suggesting that Ps-GOS may prevent bone loss in osteoporosis through Wnt/β-catenin together with BMP-2 signaling pathways. This evidence concerns the gene FZD4 and osteoporosis.