VIBRANT-IBD: Brain Effects of Non-Invasive Vagus Nerve Stimulation in IBD Remission

The VIBRANT-IBD study is a pilot, prospective, single-arm feasibility study investigating the effects of non-invasive vagus nerve stimulation (nVNS) in adults with inflammatory bowel disease (IBD) in clinical remission. Approximately 15 participants with Crohn's disease or ulcerative colitis will use the Nurosym auricular vagus nerve stimulation device daily for 28 days. Participants will undergo two magnetic resonance imaging (MRI) sessions, one before and one after the intervention. The MRI protocol will include structural imaging, diffusion-weighted imaging, MR angiography, and resting-state functional MRI (rs-fMRI) to assess brain structure and functional connectivity. Before and after the intervention, participants will complete standardised psychological and study-specific questionnaires assessing stress, anxiety, depression, fatigue, emotional functioning, body awareness (interoception), quality of life, gastrointestinal symptom-related experiences, and perceived effects of the intervention. Optional qualitative interviews will additionally explore participants' experiences of living with IBD and using vagus nerve stimulation. The study aims to evaluate the feasibility and preliminary neuropsychological and neurofunctional effects of non-invasive vagus nerve stimulation in individuals with IBD.

Inclusion Criteria Participants must meet all of the following criteria to be eligible for participation: 1. Adults aged 18 years or older. 2. Diagnosis of inflammatory bowel disease (IBD), including Crohn's disease or ulcerative colitis. 3. Clinical remission of IBD confirmed by medical evaluation. 4. Ability to provide informed consent. 5. Ability to comply with study procedures and daily use of the stimulation device. 6. No contraindications to magnetic resonance imaging (MRI). 7. No contraindications to non-invasive vagus nerve stimulation (nVNS). Exclusion Criteria Participants meeting any of the following criteria will be excluded from the study: 1. Active inflammatory bowel disease flare or clinically significant gastrointestinal symptoms. 2. Severe or life-threatening comorbid medical conditions (e.g., active cancer). 3. Contraindications to MRI, including metallic implants, pacemaker, or severe claustrophobia. 4. Contraindications to nVNS, including significant cardiac arrhythmias, severe bradycardia, active implanted electronic medical devices, recent trigeminal neuralgia, or previous vagotomy. 5. Current pregnancy. 6. Diagnosed with severe neurological or psychiatric disorders. 7. Ongoing changes in pharmacological treatment that may affect central nervous system functioning. 8. Inability to comply with study procedures or complete study assessments.