In the present study, E. coli infection caused decreased bone mass and strength accompanying with higher N.Oc/BS, circulating TRAP and CTx level, as well as comparable serum bone formation markers such as ALP and P1NP abundance, suggesting that E. coli induced osteoclastic bone resorption and thus impaired tibia quality. This evidence concerns the gene CYP27A1 and escherichia coli infection.