Capsule Delivers Electrical Current to Stomach for Appetite

Researchers at MIT have developed an ‘electroceutical’ capsule that is designed to be swallowed and which will deliver a small electrical current to the stomach wall. The device contains an external electrode that wraps around its exterior and small grooves that draw liquid away from the electrode and help it to contact the stomach wall. The technology stimulates endocrine cells in the stomach lining to secrete more of a hormone called ghrelin, which stimulates appetite and reduces nausea. The researchers hope that the device could assist patients with eating disorders or conditions such as cachexia, a wasting condition that can occur in cancer patients.

The concept of delivering electricity to the stomach to assist with gastrointestinal issues was first trialed in gastroparesis patients who experience slow GI motility, in the hope that it would enhance stomach contractions. An implanted pacemaker-like device in the stomach did help improve symptoms, but did little to increase motility. Consequently, these researchers hypothesized that the electricity was having an effect on appetite by stimulating endocrine cells in the stomach to secrete more ghrelin.

They tested their hypothesis in animals, finding that a small electrical current in the stomach did indeed increase ghrelin levels. To translate this into something that had clinical potential, they have now developed this electroceutical capsule that can be simply swallowed, avoiding the need for a surgical procedure.

“This study helps establish electrical stimulation by ingestible electroceuticals as a mode of triggering hormone release via the GI tract,” said Giovanni Traverso, a researcher involved in the study. “We show one example of how we’re able to engage with the stomach mucosa and release hormones, and we anticipate that this could be used in other sites in the GI tract that we haven’t explored here.”

The MIT team designed the capsule for maximum contact with the stomach wall. Fluids in the stomach could interfere with this, so the capsule contains small grooves with a hydrophilic coating that draw the fluid away from the electrode. The concept was inspired by the skin of the Australian thorny devil lizard, which contains tiny grooves that help to draw water towards the lizard’s mouth.

“We were inspired by that to incorporate surface textures and patterns onto the outside of this capsule,” said James McRae, another researcher involved in the project. “That surface can manage the fluid that could potentially prevent the electrodes from touching the tissue in the stomach, so it can reliably deliver electrical stimulation.”

Here’s an MIT video presenting the technology: