Although the causes of chronic indigestion aren't entirely understood, the condition typically involves the stomach not expanding and contracting properly as food is ingested. New research now suggests that in-ear nerve stimulation could help remedy that situation.
The recent study included scientists from Massachusetts General Hospital, Harvard Medical School, and Indiana's Purdue University. It involved the use of an existing therapeutic tool known as a transcutaneous auricular vagus nerve stimulator, or taVNS.
The earbud-like device is placed inside the patient's outer ear, where it painlessly stimulates the vagus nerve, which runs from the head down to the abdomen. Researchers have previously explored the use of taVNS technology for the treatment of conditions such as depression, epilepsy and even aging.
For the latest study, a specific type of taVNS was used, called a Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) device. What sets it apart from others is the fact that it delivers its electrical pulses in time with the patient's respiratory rhythm.
Both it and a non-functional dummy gadget were used in separate sessions on a total of 12 test subjects suffering from functional dyspepsia (a form of persistent indigestion). Each person proceeded to eat a meal, subsequently receiving MRI scans 15, 65 and 80 minutes after doing so.
Those scans showed that after RAVANS treatment, the ratio of stomach volume to the volume of ingested food was higher, meaning that the participants' stomachs had better expanded to accommodate the meal. Additionally, their stomachs emptied faster once the food had been digested.
Although the results are promising, further research involving a larger group of test subjects is required in order to determine factors such as the optimal doses and timings of treatments. For now at least, the scientists are advising that people afflicted with chronic indigestion do not simply buy a device and start using it.
"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," says Harvard's Dr. Roberta Sclocco, lead author of the study. "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."
Source: Experimental Biology via EurekAlert