In this study, we investigated the anti-osteoporotic effect of two fermented milk products (FMPs) fermented by Lactobacillus plantarum A41 and Lactobacillus fermentum SRK414 on a rat model of ovariectomy-induced post-menopausal primary osteoporosis.The two Lactobacillus FMPs increased the bone volume and bone mineral density (BMD) in ovariectomized (OVX) rats, and normalized the bone biomarkers in the serum. Additionally, they altered the gene expression levels of bone metabolism-related markers. Furthermore, the two Lactobacillus FMPs down regulated bone apoptosis-related genes stimulated by ovariectomy. Interestingly, the Lactobacillus FMPs decreased the levels of inflammation markers in the serum, bone, ileum, and colon of the rats. Gut bacterial populations were also affected upon FMP treatment due to increase in the abundance of the genus Lactobacillus and Faecalibacterium prausnitzii.Milk products fermented by L. plantarum A41 and L. fermentum SRK414 can exhibit anti-osteoporotic effects on post-menopausal osteoporosis via regulating the expression of bone metabolism-related markers.The two Lactobacillus FMPs used in the study can be an ideal method that has its potential of treating post-menopausal osteoporosis instead of drug treatments.