Electroacupuncture alleviates osteoarthritis and is associated with changes in gut microbiota and steroid bios

Background: Electroacupuncture (EA) is widely used for osteoarthritis (OA), but its mechanisms remain unclear. This study investigated the therapeutic effects of EA on OA in rats and its potential mechanisms.

Methods: A rat model of knee OA was established via intra-articular injection of sodium monoiodoacetate. The effects of EA on behavioral indices (paw withdrawal threshold (PWT), body weight, knee width), cartilage pathology (HE staining, Safranin O-fast green staining, TUNEL), and inflammatory factors (IL-6, IL-1β, TNF-α) were assessed. Gut microbiota and metabolites were analyzed using 16S rRNA sequencing and metabolomics. Finally, integrative analysis of differential gut microbiotas and metabolites was conducted.

Results: EA alleviated joint pain, increased PWT, reduced knee swelling, promoted cartilage repair, and inhibited chondrocyte apoptosis in OA rats. Additionally, EA decreased IL-6, IL-1β, and TNF-α levels in both serum and synovial fluid. EA altered gut microbiota composition, increasing Muribaculaceae and Lachnospiraceae at the family level, and Clostridia and Campylobacteria at the class level, while decreasing Alphaproteobacteria and Actinobacteria. Functional analysis showed changes in pathways like Biosynthesis of vancomycin group antibiotics, Folate biosynthesis, and Vitamin B6 metabolism. Metabolomics revealed that EA modulated metabolic pathways in OA rats, particularly the Steroid biosynthesis pathway. Specifically, 7-Dehydrocholesterol was decreased in the OA group compared to the Control group, while EA treatment increased its levels. Integrated analysis revealed associations between 41 gut microbiotas and 47 metabolites.

Conclusion: EA alleviated OA and was associated with changes in gut microbiota composition and steroid biosynthesis-related metabolites. These findings suggest that the gut microbiota–metabolite axis may be involved in the effects of EA on OA.