Research Progress on Using Non-drug Traditional Chinese Medicine Interventions to Treat Parkinson's Disease by Regulating the Gut-Brain Axis

Conventional Western medical treatments for Parkinson's disease (PD) still have limitations in terms of maintaining efficacy and managing adverse reactions; the "microbiota-gut-brain" axis offers a new perspective in this regard. The Braak hypothesis suggests that α-synuclein can enter the brain via the vagus nerve, and damage to the intestinal barrier and TLR4-mediated intestinal inflammation are key links in neurodegeneration along the gut-brain axis. This article reviewed the mechanisms and clinical evidence supporting the prevention and treatment of PD through therapies such as acupuncture (body, electroacupuncture, scalp, ocular, and abdominal), moxibustion, Traditional Chinese Medicine (TCM) exercises, and auricular acupuncture. In terms of mechanism, the evidence is fairly clear for electroacupuncture. It upregulated colonic GPR40/43, elevated GLP-1, and activated neuroprotective pathways such as PI3K-AKT-GSK3β through the gut microbiota–brain axis. By comparison, animal studies on other therapies mostly described broader effects, including modulation of the microbiota, repair of intestinal permeability, and inhibition of enteric inflammation. Clinical observations also suggested some symptom improvement. These therapies appear to improve motor symptoms and, to varying degrees,non-motor symptoms such as constipation, insomnia, and depression. One study reported an overall efficacy rate of 93.3% for ocular acupuncture, which was higher than the 75.6% observed for body acupuncture (single study). Still, this comparison should be treated cautiously. Most of the available evidence came from animal experiments and small-sample observational studies, with few direct cross-comparisons between therapies. For that reason, the gut-brain axis mechanisms involved in ocular acupuncture and scalp acupuncture still need closer examination and confirmation in large-sample multicenter studies.