Moderate-intensity treadmill exercise attenuates osteoporotic bone loss in ovariectomized mice via modulation of gut microbiota and glycerophospholipid metabolism.

OBJECTIVE

This study aimed to determine the key gut microbial taxa and metabolites associated with the effects of moderate-intensity treadmill exercise on bone mass in a murine model of post-ovariectomy osteoporosis, using 16S ribosomal RNA sequencing and metabolomic profiling.

METHODS

Female C57BL/6 mice (12 weeks old) were randomly allocated to one of three groups: sham-operated (SHAM), ovariectomized (OVX), and ovariectomized with exercise intervention (OVX-EX) (n = 15 per group). The OVX-EX group underwent an 8-week regimen of moderate-intensity treadmill exercise. Bone microarchitecture of the distal femur was assessed using micro-computed tomography. Gut microbiota composition was analyzed through 16S rRNA sequencing, and fecal metabolomic profiles were characterized using liquid chromatography-mass spectrometry. Spearman's correlation analysis was performed to examine the associations among differential bacterial genera, metabolites, and bone mass indices. GC-MS was used to detect short chain fatty acids in feces, and LC-MS was used to detect plasma choline content.

RESULTS

The OVX-EX mice exhibited significantly improved trabecular bone parameters, including BMD, BV/TV, and Tb.N, along with a marked reduction in the abundance of Hungatella. Moderate-intensity treadmill exercise normalized the levels of ten metabolites that were dysregulated following ovariectomy. The abundance of Hungatella is significantly correlated with eight metabolites including choline. Pathway enrichment analysis indicated glycerophospholipid metabolism as a key regulatory pathway.

CONCLUSION

Moderate-intensity treadmill exercise alleviated osteoporotic bone loss in ovariectomized mice, potentially by suppressing the proliferation of Hungatella in the gut microbiota and activating glycerophospholipid metabolism to upregulate choline levels, thereby improving bone homeostasis.