Bethesda, MD – People who suffer frequent indigestion may find relief
with a small device that hooks onto the ear known as a transcutaneous
auricular vagus nerve stimulator, or taVNS. People who used taVNS
showed significant improvements in their stomach’s ability to
accommodate and process a meal, according to a new study.

The research was scheduled to be presented at the American
Physiological Society annual meeting in San Diego this month. Though
the meeting, to be held in conjunction with the 2020 Experimental
Biology conference, was canceled in response to the COVID-19 outbreak,
the research team’s abstract was published in this month’s issue of
The FASEB Journal.

Up to 15% of U.S. adults suffer from indigestion, also known as
functional dyspepsia. The disorder can cause a premature sensation of
fullness and stomach pain after a meal. Though its causes are not well
understood, it is thought that the stomach may not stretch and
contract appropriately when food is ingested, causing pressure and
discomfort.

taVNS devices deliver short pulses of painless electrical current to
the vagus nerve, a peripheral nerve (one outside the brain and spinal
cord) that runs from the head to the abdomen. While taVNS has been
explored as a possible treatment for epilepsy, depression and a
variety of other conditions, the new research study is one of the
first to assess the potential benefits of auricular taVNS for
gastrointestinal problems. The study involved a particular type of
taVNS device, Respiratory-gated Auricular Vagal Afferent Nerve
Stimulation (RAVANS), that delivers electrical pulses in tune with the
respiratory rhythm.

“Our findings suggest that RAVANS has the ability to modulate the
stomach’s response to food ingestion, which may be impaired in
functional dyspepsia patients,” said lead study author Roberta
Sclocco, PhD, a postdoctoral fellow at Massachusetts General Hospital
and Harvard Medical School, who is also affiliated with Logan
University in Missouri. “RAVANS is a non-invasive, safe peripheral
nerve stimulation intervention and while our results are encouraging,
further research is needed to estimate the optimal dose and timings of
this intervention.”

Sclocco and colleagues tested RAVANS in 12 volunteers with functional
dyspepsia. All volunteers participated in two research sessions in
which they wore the RAVANS device or control, ate a meal and underwent
magnetic resonance imaging (MRI) scans 15, 65 and 80 minutes after
eating.

MRI scans revealed the ratio of stomach volume to the volume of
ingested food was higher during RAVANS, indicating that taVNS helped
participants’ stomachs expand to accommodate the meal. In addition,
the stomach emptied more quickly during the 80 minutes following the
meal during RAVANS.

The findings suggest that modulating the activity of the vagus nerve
with taVNS could help reduce symptoms of indigestion, though Sclocco
cautioned that patients should ask a doctor before trying it.
Stimulating the vagus nerve can potentially affect many organs,
including the heart. In addition, different taVNS technologies work in
different ways, and more research is needed to identify the best
approach for functional dyspepsia.

“While taVNS is relatively safe and without major side effects,
systems currently available on the market are all different and not
optimized for gastric applications,” said Sclocco. “Patients with
certain medical conditions may not be good candidates for this therapy
and discussing the taVNS option with a medical doctor in the context
of a patient’s overall clinical picture is always advisable.”

Sclocco noted that some people find relief from indigestion with
non-technological and non-medical approaches, such as taking slow,
deep breaths after eating. The researchers plan to test RAVANS in more
volunteers to determine which patients are likely to benefit the most.
The team is also working with industry partners to further develop
this non-invasive stimulation approach.

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About Experimental Biology 2020

Experimental Biology is an annual meeting that attracts more than
12,000 scientists and exhibitors from five host societies and more
than two dozen guest societies. With a mission to share the newest
scientific concepts and research findings shaping clinical advances,
the meeting offers an unparalleled opportunity for exchange among
scientists from across the U.S. and the world who represent dozens of
scientific areas, from laboratory to translational to clinical
research. http://www.experimentalbiology.org #expbio

About the American Physiological Society (APS)

APS is a nonprofit organization devoted to fostering education,
scientific research and dissemination of information in the
physiological sciences. The Society was founded in 1887 and today
represents 9,000 members and publishes 15 peer-reviewed journals.
http://www.the-aps.org

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according to the Institute for Scientific Information and has been
recognized by the Special Libraries Association as one of the top 100
most influential biomedical journals of the past century.

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