Exploring osteomicrobiology: A narrative review of the gut-bone axis in osteoporosis

Osteoporosis is a chronic condition that presents with decreased bone mass and changes in bone microarchitecture, leading to an increased fracture risk. While the relationship between the gut microbiome and the immune system is well established, its impact on bone health remains underexplored. This narrative review aims to investigate the relationship between gut microbiota, bone health, and osteoporosis. Key findings indicate that the gut microbiome influences bone density through various mechanisms. Specific bacterial strains such as Lactobacillus and Bifidobacterium enhance the absorption of calcium, magnesium, and phosphorus, increasing bone mineral density. Additionally, the ability to produce essential vitamins like K and B makes the gut microbiota crucial for bone synthesis and integrity. Studies also revealed notable differences in the gut microbiome composition of individuals diagnosed with primary osteoporosis (PO) compared to those who were healthy controls. PO patients exhibited higher microbiota diversity and certain distinctive phylogenetic shifts. Important bacterial taxa such as Bacteroidetes, Faecalibacterium, and Dialister exist in high numbers in PO and may be useful as biomarkers. Additionally, a correlation was found between H. Pylori infections and reduced lumbar spine bone mineral density in older males. The review identifies certain gaps in the current knowledge and research such as the role of viral and fungal components within the gut microbiome. This review highlights the potential role of the gut microbiome as a target for osteoporosis diagnosis, treatment and prevention, underscoring the need for dietary and lifestyle interventions to modify the microbiome and improve bone health.