Effect of Huoxue Tongluo Capsule on Intestinal Flora of Rats with Steroid-induced Osteonecrosis of the Femoral Head

Background Steroid-induced osteonecrosis of the femoral head (SONFH) is common and disabling. The efficacy of Huoxue Tongluo Capsule has been consistently demonstrated in the prevention and treatment of osteonecrosis of the femoral head, but there is no research on whether the treatment can be carried out by regulating the intestinal flora. Objective To establish SONFH rat model intervened by Huoxue Tongluo Capsule, analyze and compare the diversity of intestinal flora in each group of rats, screen out SONFH-specific altered bacterial genera and observe the effect of Huoxue Tongluo Capsule on intestinal flora. Methods 24 male SD rats were selected from April to October 2022 and divided into the blank group (n=8), model group (n=8) and Huoxue Tongluo group (n=8) by random number table method. The SONFH model was prepared. The Huoxue Tongluo group was given 0.63 g·kg-1·d-1 Huoxue Tongluo Capsule by gavage on the 3rd to 28th day of modeling. The blank group and model group were given an equal volume of 0.9% sodium chloride solution by gavage. After drug intervention, rat femurs were collected for HE staining and Micro-CT analysis. Rat feces were collected for 16S rDNA sequencing. α diversity analysis was used to evaluate species diversity, β diversity analysis was used to explore the similarity or dissimilarity of sample community composition, and linear discriminant analysis (LEfSe) was used to compare the differences of intestinal flora among the three groups. COG function was used to predict the intestinal flora function of the rats in the three groups. Results There were significant differences in the rate of empty bone lacunae among the three groups, and the rate of empty bone lacunae in the model group was higher than that in the blank group, while the rate of empty bone lacunae in the Huoxue Tongluo group was lower than that in the model group (P