Previous studies have shown that the gut microbiota regulates bone mass and that certain strains of Bifidobacterium longum prevent bone loss in ovariectomized (ovx) mice. A novel strain of Bifidobacterium longum (B. longum subsp. longum DSM 32947; BL) with a broad carbohydrate degradation capacity and the ability to stimulate certain lactobacilli was recently identified. In the present study, we tested if BL improves bone health in gonadal intact and ovx female mice.Ten-week-old C57BL/6 J female mice were subjected to ovx or sham surgery. One week after surgery, mice were treated with arabinoxylan oligosaccharides (AXOS; veh) or a combination of AXOS and BL for five weeks. BL treatment increased BL abundance in the cecal content.Dual-energy X-ray absorptiometry showed that BL increased total body bone mineral density in both sham and ovx mice compared with veh-treated mice (p < 0.01). Computed tomography analyses showed that BL increased trabecular bone volume fraction of the L4 vertebra, mainly due to increased trabecular thickness in both sham and ovx mice (p < 0.05). In addition, BL increased the mid-diaphyseal cortical bone area of the femur (p < 0.05) and improved its strength (p = 0.05).In conclusion, treatment with BL increases parameters for bone health in female mice.