Lactobacillus plantarum attenuates glucocorticoid-induced osteoporosis by altering the composition of rat gut microbiota and serum metabolic profile

Abstract

The results revealed that <i>L. plantarum</i> treatment significantly restored parameters of bone microstructure, with elevated bone density, increased number and thickness of trabeculae, and decreased Tb.Sp. Gut microbiota sequencing results showed that probiotic treatment increased gut microbial diversity and the ratio of Firmicutes to Bacteroidota decreased. Beneficial bacteria abundance was significantly increased (<i>Lachnospiraceae</i>_NK4A136_group, <i>Ruminococcus</i>, <i>UCG_005</i>, <i>Romboutsia</i>, and <i>Christensenellaceae</i>_R_7_group), and harmful bacteria abundance was significantly decreased (<i>Desulfovibrionaceae</i>). According to the results of serum metabolomics, significant changes in serum metabolites occurred in different groups. These differential metabolites were predominantly enriched within the pathways of Pentose and Glucuronate Interconversions, as well as Propanoate Metabolism. Furthermore, treatment of <i>L. plantarum</i> significantly increased serum levels of Pyrazine and gamma-Glutamylcysteine, which were associated with inhibition of osteoclast formation and promoting osteoblast formation. <i>Lactobacillus plantarum</i> can protect rats from DEX-induced GIOP by mediating the "gut microbial-bone axis" promoting the production of beneficial bacteria and metabolites. Therefore <i>L. plantarum</i> is a potential candidate for the treatment of GIOP.