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

Inclusion Criteria:

Age 18-65 years old (inclusive)

• Ability to give written consent and participate in behavioral intervention inEnglish

• Willingness to attend weekly treatment sessions over live video, dailyself-administered transcutaneous auricular vagus nerve stimulation (taVNS) sessions,and engage in homework during treatment

• Avoidance of alcohol, nicotine, and caffeine for 24 hours prior to study session

• Diagnosis according to the Rome IV criteria for both epigastric pain syndrome andpostprandial distress syndrome subtypes

• Stable medical treatment for functional dyspepsia (FD) during 1 month before thestudy and during the study period

Exclusion Criteria:

• Previous receipt of cognitive behavioral therapy (CBT) for gastrointestinal symptoms

• Enteral or parenteral feeding

• Previous gastrointestinal surgery, electrolyte disturbances, kidney dysfunction,renal insufficiency, or iron overload disorders

• Estimated Glomerular Filtration Rate (eGFR) < 60

• Medications that affect gastrointestinal motility in addition to medications orproducts containing tetrahydrocannabinol (THC) will be stopped at least 7 days priorto the start of the study and for the duration of the study. However,anti-depressants (SSRI's, TCA's) may be allowed in order to reduce the risk ofworsening neuropsychiatric disease, though it will be up to the study team and thePrincipal Investigator whether subjects on anti-depressants will be able toparticipate in the study

• Intellectual disability by history

• Diabetes, mitochondrial disease, severe autonomic dysfunction, and small fiberpolyneuropathy

• No active clinical acupuncture therapy

• Illicit drugs or opioid usage

• History of arrhythmias

• Current pregnancy/breastfeeding

• Contraindications for magnetic resonance imaging (MRI) (implanted ferromagneticobjects, claustrophobia)

• Weight > 450 lbs. (limit of the MRI table)

• Allergy to pineapple (used in the test meal during MRI)

• Any other condition interfering with study requirements, according to theInvestigator