Bile Acid Derivative Reverses Bone Loss by Rejuvenating Stem Cells in Mice

Researchers have found that hyodeoxycholic acid (HDCA), a bile acid derivative, can rejuvenate bone marrow stem cells and reverse osteoporosis in a mouse model of menopause. The study shows HDCA works through the TGR5-ESR1 pathway to trigger mitophagy—selective clearance of damaged mitochondria—which prevents stem cells from becoming senescent and inappropriately differentiating into fat instead of bone. This dual action addresses two key problems in age-related bone loss: accumulation of senescent cells and the shift from bone-forming to fat-forming tissue in bone marrow. The findings are particularly relevant because postmenopausal osteoporosis affects millions of women worldwide, and current treatments focus mainly on slowing bone loss rather than rejuvenating the stem cell pool. While this is still animal research, bile acids are naturally occurring molecules with known safety profiles, making translation more feasible than entirely novel compounds. The mitophagy mechanism also connects to broader longevity science, as mitochondrial quality control is increasingly recognized as central to healthy aging across multiple tissues.