Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, which results in increased fracture risk. Fractures are common in the elderly and result in increased morbidity and mortality as well as high societal costs. Fracture care is responsible for the second highest hospital costs after stroke. Currently, there are no treatments to prevent osteoporosis. Although the gut microbiome is believed to be important for bone health in humans, no other bacterial strains have been identified that correlate with fracture risk or bone strength in humans. This project has the potential to identify novel strains important for bone mass regulation and fracture risk that can lead to improving fracture prediction and novel treatments to prevent osteoporosis.