Potential application of brain-gut axis-based treatments in Long COVID and ME/CFS: a case-based systematic review.

Researchers investigated whether treatments targeting the brain-gut connection could help people with Long COVID and chronic fatigue syndrome (ME/CFS), two conditions that share symptoms like persistent exhaustion, worsening symptoms after activity, and digestive problems. The study combined a case report of one patient who improved with electroacupuncture treatment alongside a review of eight clinical trials involving 790 participants. The electroacupuncture patient received deep peroneal nerve stimulation designed to activate the vagus nerve, which connects the brain and gut. Over 12 weeks, the patient showed significant fatigue reduction, with mental fatigue and motivation improving first, followed by physical fatigue (though symptoms temporarily worsened before improving). The systematic review found that treatments modifying gut bacteria (like probiotics combined with prebiotics) and certain herbal therapies reduced fatigue and changed specific bacterial populations or brain metabolism. Among nerve stimulation approaches, transcranial direct current stimulation combined with exercise helped fatigue, while standalone stimulation methods showed less benefit. The findings suggest that therapies targeting the brain-gut axis may reduce fatigue by calming brain inflammation, rebalancing gut bacteria, and healing the intestinal lining. Electroacupuncture-based vagus nerve stimulation appears promising for patients with severe or treatment-resistant symptoms, though the evidence comes primarily from this single case report. Larger, well-designed studies are needed to confirm these benefits and determine optimal treatment approaches. Patients interested in acupuncture for Long COVID or ME/CFS should seek treatment from a licensed acupuncturist with experience in neurological and complex chronic conditions.

This study combined a case report with a systematic review of RCTs (n=8, 790 participants) examining brain-gut axis interventions for ME/CFS and Long COVID. The case involved electroacupuncture-based deep peroneal nerve stimulation to potentiate vagal reflexes, assessed via Multidimensional Fatigue Inventory over 12 weeks. The patient demonstrated significant total fatigue reduction, with early improvements in motivation and mental fatigue, delayed physical fatigue improvement, and transient systemic flares. Among reviewed RCTs, four evaluated gut microbiome modulation (synbiotics, herbals) showing fatigue/PEM benefits with altered bacterial populations or CNS metabolism; four examined nerve stimulation, with tDCS plus exercise showing efficacy while standalone tDCS, auricular, or peripheral TENS had limited benefit. Clinical takeaway: Brain-gut axis interventions, particularly EA-based vagal stimulation, may benefit severe or refractory ME/CFS and Long COVID cases through neuroinflammation modulation, microbiome restoration, and epithelial barrier improvement. Larger mechanistic trials needed to establish protocols and therapeutic targets.