AUTHOR=Zhao Xian , Wu Bin , Han Pengli , Wang Zhongyu , Cao Renwei , Chen Shuo , Cheng Cheng , Lian Hongkai , Zha Yejun , Li Minjuan TITLE=Gut microbiota-metabolome remodeling associated with low bone mass: an integrated multi-omics study in fracture patients JOURNAL=Frontiers in Molecular Biosciences VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2025.1646361 DOI=10.3389/fmolb.2025.1646361 ISSN=2296-889X ABSTRACT=BackgroundThe gut microbiota is increasingly implicated in the pathogenesis of osteoporosis, but its role in the specific context of fracture patients remains poorly defined. High-resolution multi-omics studies are needed to elucidate the complex interplay between microbes, their metabolites, and bone health. This study aimed to characterize the gut microbial and fecal metabolic signatures associated with low bone mass in fracture patients.MethodsWe conducted a cross-sectional study of 51 fracture patients, stratified by bone mineral density into Normal, Osteopenia, and Osteoporosis groups. For key analyses, the latter two groups were combined into a Low Bone Mass (LBM) group. We performed shotgun metagenomic sequencing and untargeted liquid chromatography-mass spectrometry metabolomics on fecal samples. An integrated bioinformatics and statistical analysis were used to identify differential taxa and metabolites, construct correlation networks, and build diagnostic biomarker models.ResultsPatients with LBM exhibited a distinct gut microbial and metabolic profile compared to controls. A notable finding was the unexpected enrichment of Lachnospira eligens in the LBM group, despite its previous association with gut health. In contrast, traditionally beneficial taxa such as Bifidobacterium species and Bacteroides stercoris were markedly depleted. Metabolomic analysis identified 127 differential metabolites, and integrated analysis revealed a strong correlation between L. eligens and inflammation-associated metabolites, including N-acetylneuraminate. A diagnostic model incorporating four key bacterial species accurately discriminated LBM patients from controls with an area under the curve (AUC) exceeding 0.9.ConclusionOur findings reveal a significant remodeling of the gut microbiota-metabolome axis in fracture patients with low bone mass, highlighting a context-dependent, potentially pathological role for the typically beneficial species L. eligens. These distinct microbial and metabolic signatures suggest potential mechanistic insights into the gut-bone axis and represent promising, non-invasive biomarkers for assessing skeletal health.