Introduction

Low back pain (LBP), a widely prevalent and costly disease around the world, is mainly caused by intervertebral disc (IVD) degeneration (IDD). Numerous factors may trigger this degenerative process, for example, aging, inflammation, genetic susceptibility and trauma. Modic changes (MCs) is one of disc degeneration. Research have found Modic changes were present in 46% of patients with chronic low back pain compared with only 6% of the general population The pathological alteration of microbiome composition, also known as dysbiosis, has been associated with diseases linked to damaged bone metabolic disorders such as osteoarthritis, rheumatoid arthritis (RA), ankylosing spondylitis (AS), adolescent idiopathic scoliosis (AIS) and osteoporosis. However, the connection between the microbiome and MCs has not been well understood but is believed to happen through translocation of the bacteria across the gut epithelial barrier, regulation of the mucosal and systemic immune system, and regulation of nutrient absorption, metabolites formation at the gut epithelium. We believe that the microbiome has the potential to serve as a biomarker of IDD and a target for LBP treatment.

Methods

We performed a case–control study to compare the faecal microbiome of LBP with/without patients and healthy control by 16S ribosomal RNA (rRNA) sequencing and metagenomics. The overwhelming mass of research supports gut microbiome could produce some end products of fermentation, these products may enter our circulation system by blood and cause some influence on our physiology. The serum metabolome can provide the functional redout of the gut microbiome. So to address the causative relationship between gut dysbiosis and LBP, we also use the untargeted metabolomic methods to detect the serum metabolome.

Results

We identified 3 bacterial species showing notable differences in abundance between MDD patients and healthy controls (HCs). Patients with LBP+MCs were mainly characterized by increased abundance of the species are Erysipelotrichaceae bacterium and Eubacterium bioforme and decreased abundance of the species Ruminococcus torque. Besides, the metabolomics enriched 7 pathways, including Valine, leucine and isoleucine degradation, Nicotinate and nicotinamide metabolism Sphingolipid metabolism, Amino sugar and nucleotide sugar metabolism, Neomycin, kanamycin and gentamicin biosynthesis, Porphyrin and chlorophyll metabolism, Drug metabolism - cytochrome P450. Disturbed microbial genes and serum metabolites were consistently mapped to Valine, leucine and isoleucine degradation metabolism. Our findings provide a deep insight into understanding of the roles of disturbed gut ecosystem in LBP with MCs.

Discussion

This study suggests that the gut microbiome of patients with LBP is dysbiotic and contributes to disease pathogenesis. More invitro works need to do for detecting the mechanism about microbiome and the development of MCs