Sika deer velvet antler protein extract modulater bone metabolism and the structure of gut microbiota in ovariectomized mice

Osteoporosis is a systemic osteopathy characterized by bone metabolism disorders that become more serious with age increases in postmenopausal women. Recent studies have found that antler protein is the main bioactive component of cervus pantotrichum, and it has a positive regulatory effect on bone metabolism and can improve estrogen level. This study aimed to investigate the effect of velvet antler extract (VAE) on the prevention of osteoporosis and the modulation of gut microbiota in ovariectomized (OVX) mice. OVX mice treated with 12 weeks of VAE exhibited higher levels of serum BGP, Ca2+, CT, and HyP (p < .05). Micro-CT scans showed that VAE significantly elevated bone volume fraction (BV/TV), trabecular bone number (Tb.N), trabecular bone thickness (Tb.Th), trabecular bone connection density (Conn.D), decreased trabecular separation (Tb.Sp), and structural modality index (SMI) than untreated OVX mice. The right tibial retinaculum in the VAE group was clearer, with a clearer reticular structure, smaller gaps, a tighter distribution, and a more orderly arrangement. The gut microbiota of the cecal contents was analyzed by 16 s rDNA amplicon sequencing. The data indicated that VAE modulated the species, numbers, and diversity of the gut microbiota in OVX mice. Ovariectomy caused dysbiosis of the intestinal microbiota by increasing the ratio of Firmicutes to Bacteroidetes in mice, but the ratio decreased after treatment with VAE. These results suggest that VAE has a therapeutic effect on OVX mice via modulate bone-related biochemical markers in serum and structure of gut microbiota.