Transcutaneous electrical nerve stimulation treated anterior talo-fibular ligament injured rat through the gut-joint axis and intestinal microbiota

Objective This study demonstrated that transcutaneous electrical nerve stimulation (TENS) and its induced fecal microbiota transplantation (FMT) could treat anterior talo-fibular ligament (ATFL) injury rat and modify the intestinal microbiota via the gut-joint axis. Methods An ATFL injury model was duplicated and treated with low, medium, or high-intensity of TENS. After 1, 2, and 3 weeks of TENS treatment, the improvements and the expression levels of NOD2/IL-6/NF-κB/BMP-2/TGF-β were measured. The intestinal microbiota was analyzed via 16S rDNA sequencing. After FMT which induced by TENS, the improvement of ATFL injury rat was analyzed. Results After TENS treatment, compared with the model control group, the bio-mechanical, gait, bone mineral density (BMD), etc. parameters were elevated in the TENS groups ( p < 0.05); the expression of NOD2/IL-6 decreased and the BMP-2/TGF-β increased in the TENS groups ( p < 0.05). The intestinal microbiota was altered, including increases in the abundances of Erysipelotrichaceae , Lachnospira , Eubacterium , Phascolarctobacterium , and Alloprevotella . After FMT, similar improvements were found in ATFL injury rats. Conclusion TENS ameliorated ATFL injury rat by regulating the NOD2/IL-6/NF-κB/BMP-2/TGF-β and changed the intestinal microbiota through the gut-joint axis. Dominant intestinal microbiota was associated with FMT and could improve ATFL injury rat.