摘要:Using retinoic acid to inducer, we successfully established a rat model of secondary osteoporosis and verified the preventive effect of Lactobacillus fermentum ZS40 (ZS40) on secondary osteoporosis. Serum biochemical indicators showed that ZS40 can effectively slow down bone resorption caused by retinoic acid, increase blood content of calcium, phosphorus, bone alkaline phosphatase, bone gla protein, and insulin‐like growth factor 1, and decrease blood content of tartrate‐resistant acid phosphatase (TRAP) 5b. qRT‐PCR results showed that ZS40 could upregulate mRNA expressions of β‐catenin , Wnt10b , Lrp5 , Lrp6 , Runx2 , ALP , RANKL , and OPG , and downregulate mRNA expression of DKK1 , RANK , TRACP, and CTSK in the rats’ spinal cord. Results following TRAP staining showed that ZS40 could slow down retinoic acid‐induced formation of osteoclasts. Micro‐CT results showed that ZS40 could reduce Tb.Sp, increase BV/TV, Tb.N, Tb.Th, and ultimately increase bone mineral density of rats in vivo. These findings indicate that ZS40 might have a potential role in preventing retinoic acid‐induced secondary osteoporosis in vivo.