An integrated fecal metabolomic based on 1 H-NMR and UPLC-QTOF-MS revealed the preventive mechanism of Gushudan on glucocorticoid-induced osteoporotic rats.

Gushudan (GSD) has the effect of strengthening bones and nourishing kidneys. However, its specific intervention mechanism still remains unclear. In this study, to investigate the pathogenesis of glucocorticoid-induced osteoporosis (GIOP) and the preventive mechanism of GSD on GIOP, fecal metabolomics based on 1 H-NMR and ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry method was established. The changes in endogenous metabolites and the relevant metabolic pathways in the control group, model group, and GSD treatment group were investigated via multivariate statistical analysis. As a result, a total of 39 differential metabolites were identified. Of these, 22 metabolites, such as L-methionine, guanine, and sphingosine, were newly discovered as differential metabolites of GIOP. Amino acid metabolism, energy metabolism, intestinal flora metabolism, and lipid metabolism were significantly changed in the fecal profiles of GIOP rats, and GSD could play an anti-osteoporosis role by regulating these metabolic pathways. Finally, compared with our previous study of the GSD to prevent kidney yang deficiency syndrome, this study suggested that there were some identical differential metabolites and metabolic pathways. It showed that there was some correlation among the metabolic profiles of the intestine, kidney, and bone in GIOP rats. Therefore, this study offered new insights into the in-depth understanding of the pathogenesis of GIOP and the intervention mechanism of GSD.