Effects of Eclipta prostrata on gut microbiota of SAMP6 mice with osteoporosis

Traditional Chinese medicine (TCM) has been extensively studied for its preventive and treatment properties toward osteoporosis (OP). Pharmacological studies have shown that TCM Eclipta prostrata induce anti-OP effects. Considering the growing evidence demonstrating that gut microbiota (GM) is related to OP, we aimed to study the GM-dependent function and mechanism of E. prostrata for preventing OP in mice.Bone micro-structure was obtained using micro-computed tomography (micro-CT) and bone-relating factors were detected by molecular biological test. High-throughput sequencing of the 16S rRNA V4 region was performed for GM diversity analysis. Growth effects of E. prostrata on potential targeted strains Lactobacillus and Lactococcus were investigated by in vitro bacterial assay. By feeding Lactobacillus and Lactococcus in mice, GM and bone condition were analysed.Bone micro-structure was significantly improved by E. prostrata with a potential mechanism of inhibiting osteoclast, increasing the number of osteoblasts and regulating the dynamic balance of bone absorption and formation. Sequencing results indicated that E. prostrata altered the bacterial community. The abundance of bacteria genera Lactobacillus and Lactococcus was markedly decreased in individuals with OP and positively correlated with high dose of E. prostrata. GM of the low-dose E. prostrata-fed group did not significantly differ from that of the chow-fed OP group, which was consistent with bone structure test results. Moreover, E. prostrata could promote Lactobacillus and Lactococcus growth in vitro. GM was altered and bone condition was improved via bacterial feeding in vivo.Our findings suggested that E. prostrata might be a novel therapy for OP prevention by targeting GM.