Obesity Review

taVNS and the Gut–Brain Axis in Obesity

Transcutaneous auricular vagus nerve stimulation modulates the microbiota and viscerosensory signals that influence satiety and fat accumulation.

Prof. Elena Rossi

Prof. Elena Rossi

Dept. of Clinical Neuroscience, University of Milan · 15 Apr 2026

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Key Takeaways

  • taVNS acts on the nucleus tractus solitarius and modulates hypothalamic satiety responses.
  • Gut microbiota shifts mediate part of the observed metabolic effect.
  • Left auricular stimulation is associated with greater reduction in high-calorie food craving.

Gut–brain axis

Obesity disrupts bidirectional communication between the microbiota and the central nervous system. taVNS represents a non-invasive therapeutic bridge between autonomic modulation and peripheral metabolic signals.

Clinical results

In available controlled trials, taVNS produced significant reductions in body weight and food desire compared with sham, with a favourable safety profile.

"Modulating the vagus nerve means acting simultaneously on the brain, the gut, and low-grade systemic inflammation."
— Prof. Elena Rossi, University of Milan

Current limitations

Standardisation of stimulation parameters and long-term data on weight maintenance and metabolic remission are still lacking.

References

  1. Lopez P. et al. (2025). taVNS, gut microbiota and body weight: a 24-week trial. Gut, 74(2), 301–312.
  2. Chen Y. et al. (2024). Vagal afferents and hypothalamic control of feeding after auricular stimulation. Nature Metabolism, 6(8), 1455–1468.
Prof. Elena Rossi

Prof. Elena Rossi

Full Professor of Clinical Neuroscience at the University of Milan. Director of the BMH Neuromodulation Lab. Her research focuses on non-invasive brain stimulation for metabolic and psychiatric disorders. She has authored over 80 peer-reviewed publications and led 6 multicentre clinical trials.