| Objective Based on the brain-gut-bone axis, the effects of Zuogui Pill on neuronal degeneration in the hippocampus, changes in intestinal flora, and bone loss were investigated in senile mice osteoporosis (SOP) model. Methods The SOP model was constructed with intraperitoneal injection of D-galactose (120 mg/kg) for 12 consecutive weeks. The mice were randomly divided into the blank group, the model group, the Zuogui Pill high-dose group, and the Zuogui Pill low-dose group. Mice received Zuogui Pill for 8 weeks, and then the Morris water maze experiment was carried out to detect the cognitive function of the mice. Brain tissue oxidative stress indexes were detected in each group after sampling. Hippocampal nidus neuron integrity was detected with Nissen staining. Intestinal flora diversity was detected using 16S rRNA. Bone loss was detected with small animal X-ray machine. Bone metabolism indexes were detected in mice serum. Bone metabolism pathway-related proteins were detected with immunohistochemistry. The results of the analysis of serum bone metabolism factors, brain tissue oxidative stress factors, and the cognitive function of mice in the intestinal flora were investigated using Spearman's assay. The association analysis of serum bone metabolism factor, brain tissue oxidative stress factor, and differential flora in intestinal flora was carried out with Spearman analysis. Results Compared with the model group, the Zuogui Pill administration group significantly shortened the escape latency time (P<0.05), significantly increased the number of nidamental vesicles in the hippocampus (P<0.01), and increased the content of antioxidant enzymes in the brain tissue (P<0.05). The relative abundance of Bacteroidota in the intestinal flora of the model group mice increased significantly at the gate level (P<0.01). The relative abundance of Verrucomicrobiota and other bacterial flora was significantly higher (P<0.05) and the relative abundance of Bacteroidota was significantly lower (P<0.05) in the Zuogui Pill administration group. Bone loss in the femoral epiphysis and diaphysis region of mice was ameliorated. Serum bone metabolism indexes improved significantly (P<0.01). The ratio of OPG/RANKL protein content increased significantly (P<0.01). Correlation analysis showed that catalase was positively correlated with Proteobacteria in intestinal flora (P<0.01) and negatively correlated with Prevotellaceae in NK3B31 group (P<0.01). Conclusion Zuogui Pill improves the abundance of intestinal flora in SOP mice according to the brain-gut-bone axis, which in turn alleviates the degenerative neuronal lesions in the hippocampus, and regulates the OPG/RANK/RANKL pathway to alleviate the loss of bone mass. |