Gut-disc axis: A Mendelian randomization study on the relationship between gut microbiota and cervical spondylosis

The gut-disc axis, which refers to the interaction between gut microbiota and bone health, has recently garnered widespread attention in the scientific community. However, it remains to be determined whether gut microbiota directly induces cervical spondylosis (CS). This study employed a bidirectional 2-sample Mendelian randomization (MR) analysis to explore the potential causal link between gut microbiota and CS. We initially used the inverse variance weighted method for preliminary estimation and supplemented it with other MR methods, including MR-Egger, weighted median, weighted mode, and simple mode. Furthermore, we utilized the Cochrane Q test, MR-PRESSO global test, and MR-Egger intercept test to assess possible pleiotropy and heterogeneity. Ultimately, we conducted a bidirectional MR study to investigate potential reverse associations between gut microbiota and CS. The preliminary MR analysis identified 27 gut microbiota significantly associated with CS, of which 12 may be contributing factors, while 15 may have protective effects. The reverse MR analysis further revealed a potential causal relationship between CS and 24 gut microbiota. In this study, no significant heterogeneity or pleiotropy was detected. Through MR analysis, we uncovered a significant causal relationship between gut microbiota and CS, providing new perspectives for the prevention and treatment of CS, especially in the modulation of the microbiota.