The role of electroacupuncture in modulating gut microbiota and alleviating lumbar disc herniation in rats

BACKGROUND: Lumbar disc herniation (LDH) is a common disease, and the resulting low back pain seriously affects patients' daily life and work. Previous studies have demonstrated the clinical efficacy of electroacupuncture (EA) treatment in alleviating LDH. Recent studies have shown a link between the gut microbiota and LDH. However, the relationship between the regulatory effect of electroacupuncture therapy on gut microbiota and the improvement of LDH is still not fully understood. METHODS: Eighteen SPF female Sprague-Dawley (SD) rats were randomly assigned to three groups: control group (CON), lumbar disc herniation group (LDH), and LDH + electroacupuncture group (EA). A rat model of lumbar disc herniation was established through autologous nucleus pulposus transplantation. Starting from the second day after LDH induction, the EA group received electroacupuncture treatment once a day for a total of 7 times (2 mA, 2/15 Hz, 30 min/day) at bilateral Weizhong (BL40). The pathological changes of intervertebral disc tissue of rats in each group were observed, and the expression of inflammatory factors and extracellular matrix (ECM)-related proteins in intervertebral disc tissue of rats in each group were detected. Changes in gut microbiota of rats in each group were detected by 16 S ribosomal DNA (rDNA) sequencing. RESULTS: EA treatment significantly improved the pathological damage and inflammatory response of intervertebral disc tissue in LDH rats, and maintained the balance of ECM in intervertebral disc tissue in LDH rats. Through 16 S rDNA sequencing analysis, it was found that the abundance of OTU/ASV in gut microbiota in LDH model rats was significantly reduced. However, EA treatment can partially reverse the changes in OTU/ASV abundance of EA treatment. At the genus level, the abundance of Flavonifractor, Christensenella, Lachnospiraceae_UCG-010, Fournierella, Prevotellace_Ga6A1_group, Eubacterium and Holdemania were increased in the LDH group, while the abundance of these bacterial groups was significantly down-regulated after EA treatment. The abundance of RF39_genus and Coriobacteria_genus were decreased in the LDH group, but the abundance of these bacterial groups increased significantly after EA treatment. CONCLUSION: These findings suggest that EA at BL40 point has a significant therapeutic effect on LDH rats, which may be achieved by regulating the gut microbiota.