Postmenopausal osteoporosis (PMOP) is a systemic metabolic bone disease caused by the decrease in estrogen levels after menopause. It leads to bone loss, microstructural damage, and an increased risk of fractures. Studies have found that the gut microbiota and its metabolites can regulate bone metabolism through the gut-bone axis and the gut-brain axis. As research progresses, PMOP has been found to be associated with gut microbiota dysbiosis and Th17/Treg imbalance. The gut microbiota is closely related to the development and differentiation of Treg and Th17 cells. Among them, the metabolites of the gut microbiota such as short-chain fatty acids (SCFAs) can regulate the differentiation of effector T cells by acting on molecular receptors on immune cells, thereby regulating the bone immune process. The multifaceted relationship among the gut microbiota, SCFAs, Th17/Treg cell-mediated bone immunity, and bone metabolism is eliciting attention from researchers. Through a review of existing literature, we have comprehensively summarized the effects of the gut microbiota and SCFAs on PMOP, especially from the perspective of Th17/Treg balance. Regulating this balance may provide new opportunities for PMOP treatment.
Humans ; Gastrointestinal Microbiome/immunology* ; Fatty Acids, Volatile/metabolism* ; Osteoporosis, Postmenopausal/immunology* ; Female ; T-Lymphocytes, Regulatory/metabolism* ; Th17 Cells/metabolism* ; Dysbiosis/immunology* ; Bone and Bones/metabolism*

Animals ; Female ; Humans ; Integrative Medicine ; trends ; Osteoporosis, Postmenopausal ; genetics ; immunology ; therapy

The aims of this study were to investigate the relationships between the production of interleukin-1 (IL-1), and IL-6 system by whole blood cells, and bone mineral density (BMD), and polymorphisms in IL-1 system and IL-6 gene in postmenopausal Korean women. The production of IL-1alpha, IL-1beta, IL-1 receptor antagonist (IL-1ra), IL-6, and soluble IL-6 receptor (sIL-6r) by lipopolysaccharide-stimulated whole blood cells was measured by ELISA in 110 subjects. Serum osteocalcin, C-telopeptide of type I collagen, and BMD at lumbar spine and proximal femur were measured. IL-1alphaC(-889)T polymorphism, IL-1beta C(-511)T polymorphism, 86-base pair variable number tandem repeat polymorphism in the IL-1ra gene, and IL-6 C(-634)G polymorphism were analyzed. The production of IL-1beta correlated positively with BMD at femoral neck, whereas the production of other ILs did not correlate with BMD at the skeletal sites examined. No significant differences in the production of ILs were observed among normal, osteopenic and osteoporotic postmenopausal women, and among the different IL system polymorphisms groups studied. No correlation between bone turnover markers and the production of ILs was noted. In conclusion IL-1beta may regulate bone metabolism at femoral neck, and the IL system polymorphism do not affect the production of ILs by whole blood cells.
Aged ; Blood Cells/drug effects/immunology ; Bone Density/*genetics/*immunology ; Bone Diseases, Metabolic/blood/genetics/immunology ; Cytokines/*biosynthesis/blood ; Female ; Humans ; In Vitro ; Interleukin-1/biosynthesis/blood/genetics ; Interleukin-6/biosynthesis/blood/genetics ; Interleukins/*genetics ; Lipopolysaccharides/pharmacology ; Middle Aged ; Osteoporosis, Postmenopausal/blood/genetics/immunology ; *Polymorphism, Genetic ; Receptors, Interleukin-6/biosynthesis/blood/genetics ; Research Support, Non-U.S. Gov't ; Sialoglycoproteins/biosynthesis/blood/genetics