Effects of transcutaneous electrical nerve stimulation based on wrist-ankle acupuncture theory on the skeletal muscle repair and gut microbiota modulation in rats with gastrocnemius muscle injury.

Background: In recent years, the gut microbiota has attracted considerable attention as a critical regulator of inflammation and metabolism, particularly due to its involvement in muscle repair via the "gut-muscle axis." This study aims to evaluate the therapeutic efficacy of transcutaneous electrical nerve stimulation based on wrist-ankle acupuncture theory (WAA-TENS) in a rat model of gastrocnemius muscle injury, and subsequently to explore whether its effects are associated with alterations in the gut microbiota. Methods: Twenty-four 8-week-old rats were randomly allocated to three groups ( Results: Behavioral studies indicated that WAA-TENS significantly increased the pain threshold of model rats ( Conclusion: WAA-TENS effectively alleviated mechanical allodynia, attenuated local inflammation, and promoted muscle repair in a rat model of CFA-induced gastrocnemius injury. Concurrently, WAA-TENS was associated with significant alterations in gut microbiota composition, including the enrichment of Lactobacillus reuteri. These parallel findings suggest a potential association between WAA-TENS-induced microbiota modulation and its therapeutic effects on skeletal muscle, providing a hypothesis-generating foundation for future mechanistic investigations into the gut-muscle axis. The causal contribution of specific microbial taxa to muscle repair, however, remains to be established.