Disease-associated gut microbiome and metabolome changes in chronic low back pain patients with bone marrow lesions

Chronic low back pain (LBP) is the leading cause of global disability. Vertebral bone marrow lesions (BMLs), one etiological factor for chronic LBP, are MRI signal changes in the vertebral bone marrow that extend from the disc endplate. The adipogenesis of bone marrow mesenchymal stem cells (BM-MSCs) could explain fatty replacement (FR) in normal bone marrow. FR is the most common type of BMLs. Here we show how the gut microbiome and serum metabolome change and how they interact in LBP patients with or without FR. The serum metabolome of chronic LBP patients with FR is characterized by decreased levels of branched-chain amino acids (BCAAs), which correlate with a gut microbiome that has important capability to regulate BCAA degradation pathway. Ruminococcus gnavus, Roseburia hominis and Lachnospiraceae bacterium 8 1 57FAA are identified as the main species driving the association between biosynthesis of BCAAs and BM-MSCs metabolism in LBP with FR individuals. In vitro work demonstrates that BCAAs can induce the adipogenesis of BM-MSCs by activating the SIRT4 pathway. Our findings provide a deep insight into understanding the role of the disturbed gut ecosystem in FR and LBP. ### Competing Interest Statement The authors have declared no competing interest.