Functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C) are prevalent disorders of gut-brain interaction with limited effective treatments. The vagus nerve exerts considerable influence on the gastrointestinal (GI) tract, indicating that noninvasive electrical neuromodulation targeting this nerve could provide a promising therapeutic avenue for both FC and IBS-C. This review explores several emerging noninvasive neuromodulation techniques involving the vagus nerve, such as transcutaneous auricular vagal nerve stimulation, percutaneous electrical nerve field stimulation, and transcutaneous electrical acustimulation. The clinical applications of these methods in managing FC and IBS-C are evaluated. Existing evidence supports the efficacy and safety of noninvasive neuromodulation in relieving symptoms of these conditions. Future investigations should aim to refine these techniques, advance device technology, and further clarify the mechanisms of action.

Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity, impaired epithelial barrier function, and autonomic dysregulation, and has a higher prevalence in women. Most preclinical studies rely primarily on male animals, limiting the translational relevance of these findings to the female population. To address this gap, we investigated the effects of chronic bilateral electrical acustimulation (BEA) at acupoint ST36 in male and female rats, and sacral nerve stimulation (SNS) in male rats using an IBS model induced by neonatal acetic acid irritation. Visceral sensitivity was assessed using electromyographic responses to colorectal distension, and barrier integrity was evaluated using transepithelial electrical resistance and tight junction protein expression. Circulating norepinephrine (NE) and pancreatic polypeptide (PP) levels were measured as autonomic biomarkers. Additionally, acetylcholine (ACh) release and tumor necrosis factor-alpha (TNF-α) levels were assessed to evaluate the activation of the cholinergic anti-inflammatory pathway. Both BEA and SNS significantly decreased visceral hypersensitivity and improved the barrier function. Dysregulation of NE and PP levels was normalized following treatment, with females showing greater PP modulation, suggesting sex-dependent autonomic responses. BEA and SNS also increased ACh release and reduced TNF-α levels. Together, our results highlight BEA as a non-invasive modality with therapeutic potential comparable to that of invasive SNS for managing IBS-associated visceral pain. PERSPECTIVE: BEA and SNS effectively reduced visceral hypersensitivity and restored intestinal barrier integrity in a preclinical model of IBS. These therapies normalize autonomic balance and, by activating the cholinergic anti-inflammatory pathway, suppress inflammation. Notably, BEA provides a non-invasive, clinically viable alternative to SNS with comparable therapeutic efficacy across sexes.

Disorders of gut-brain interaction (DGBI), including irritable bowel syndrome (IBS), have a significant impact on patients, reducing their quality of life and work efficiency. Pharmacological therapy is primarily used as a frontline treatment option for treating IBS. However, owing to the heterogeneous characteristics of IBS and its limited pathophysiological understanding, pharmacological therapy is rather disappointing. Therefore, patients with IBS often use alternative therapies, such as electrical neuromodulation, to treat IBS-related symptoms. Neuromodulation includes invasive and noninvasive methods via implanted electrodes and transcutaneous electrodes, respectively. In this manuscript, we reviewed the therapeutic effects of several electrical neuromodulation approaches, including sacral nerve stimulation, spinal cord stimulation, auricular vagal nerve stimulation, and transcutaneous electrical acustimulation, on the symptoms of IBS. Additionally, we discussed the potential mechanisms, adverse effects, advantages, and disadvantages of different neuromodulation treatment methods.

Fibromyalgia Syndrome (FMS) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and localized tenderness. Transcutaneous Electrical Acustimulation (TEA) is a non-invasive therapy that combines Traditional Chinese Medicine with electrical stimulation at specific acupoints. Previous studies have shown that TEA is effective in treating pain-related conditions. This study aims to evaluate the efficacy and mechanisms of TEA treatment for FMS.

Previous research has identified a variety of factors that contribute to the development and maintenance of wounds. Concurrently, electroacupuncture has been demonstrated to facilitate wound healing. However, the effects of transcutaneous electrical acustimulation (TEA) on wound healing, as well as its relationship with key factors such as Wnt3a, TGF-β, Akt, c-Myc, VEGF-A, SP1, nitric oxide (NO), and mitochondrial function, remain largely unexplored. We hypothesize that TEA will activate the signaling factors and enhance mitochondrial functions to promote the repair of skin wounds in mice. An in vivo experimental study was conducted utilizing mouse models with skin wounds. The study comprised three groups: a TEA treatment with wound group, a skin wound model group, and a control group. Wound areas were measured by calculating the product of the length and width of each wound using calipers. Single-cell suspensions were prepared by excising the wound and the immediately surrounding tissue. These suspensions were stained with Trypan blue to assess cell viability, with specific probes to measure the rate of reactive oxygen species (ROS) positivity, and with reagents to quantify NO content. Western blotting (WB) was employed to evaluate protein levels associated with tissue changes, while quantitative polymerase chain reaction (qPCR) was used to assess RNA expression levels. Immunofluorescence staining was performed to visualize protein content and other relevant cellular structures within tissue sections. TEA exhibited anti-inflammatory properties and promoted wound healing in mice. Western blot analysis revealed that TEA enhanced the expression of proteins associated with Wnt3a, TGF-β, Akt, c-Myc, VEGF-A, and SP1 during the wound healing process. Immunofluorescence staining of tissue sections indicated that TEA upregulated the expression of COL1A1, MFN1, GRP75, GRP78, GRP75/ROS, GRP78/ROS, ISCU, and UCP1 while downregulating FIS1. Additionally, qPCR results demonstrated that TEA promoted the expression of IL-10 and miRNA205-5p while inhibiting MMP9 levels. TEA modulates various signaling molecules, influences chaperone proteins related to stress recovery responses, along with mitochondrial dynamics and metabolism.

The purpose of this study was to investigate the effects of different electrical stimulation methods (bilateral electroacupuncture (BEA), unilateral EA (UEA), transcutaneous electrical acustimulation (TEA, stimulation via surface electrodes placed at acupoints), and sacral nerve stimulation (SNS)) on visceral pain in a rodent model of irritable bowel syndrome (IBS). Ten-day-old male and female pups were treated with 0.2 ml of 0.5% acetic acid (AA) solution. Visceral sensitivity was assessed using an electromyogram (EMG) in response to graded colorectal distension. In the first experiment, bilateral EA at ST36 acupoint was performed with different parameters in male rats to determine the best stimulation parameters. In the second experiment, male rats were randomly assigned into the Sham, BEA, UEA, TEA, and SNS groups to determine the best stimulation method. Lastly, the AA-treated female rats were randomly assigned into the BEA and sham groups to investigate a potential treatment difference between the sexes. Two distinct sets of stimulation parameters were used: Set 1 (100 Hz, 0.5 ms pulse width, 0.1 s ON, 0.4 s OFF, 0.4-3.0 mA current) and Set 2 (25 Hz, 0.5 ms pulse width, 2 s ON, 3 s OFF, 0.4-3.0 mA current).Results (1) The parameter set of 100Hz was found to be most effective in reducing visceral pain. (2) Both acute UEA and TEA effectively relieved visceral pain, whereas acute SNS did not exhibit such an effect. (3) Acute BEA improved visceral pain in both male and female rats.Conclusions These findings suggest that transcutaneous ST36 stimulation is as effective as direct ST36 stimulation and unilateral ST36 stimulation is comparable to bilateral stimulation. Development of a novel therapy using unilateral transcutaneous ST36 stimulation is warranted.

This study evaluates the efficacy of integrating percutaneous electrical nerve stimulation at the pericardium 6 (PC6) acupuncture point through a wearable acustimulation device with standard pharmacological prophylaxis to prevent postoperative nausea and vomiting (PONV) compared with pharmacological prophylaxis alone in patients undergoing laparoscopic abdominal surgery.