Synergistic Gut-brain Axis Modulation Via Vagal Stimulation and Cognitive Behavioral Therapy in Functional Dyspepsia

The primary aims of this randomized, single-blinded, 2x2 sham-controlled trial are to 1) evaluate synergistic impact of 8-weeks of transcutaneous auricular vagus nerve stimulation (taVNS) + cognitive-behavioral therapy (CBT) on post-meal gut-brain communication; 2) determine the sequential relationship between treatment-associated changes in gastrointestinal-related anxiety and both clinical functional dyspepsia (FD) improvements and meal-induced physiological outcomes; 3) investigate whether post-treatment changes in gut-brain physiology mediate improvements in FD clinical outcomes. Using a fully non-invasive framework including gastric and brain magnetic resonance imaging (MRI) and taVNS, the investigators aim to evaluate the potential synergy of taVNS and CBT in FD, by assessing the gut-brain physiological response to prandial challenge, linking physiological with symptom improvements.