Electrical stimulation capsule reduces fluid intake in obese patients

An ingestible Intraluminal Gastrointestinal Stimulation Capsule (IGSC) system designed to reduce fluid intake in obese people has demonstrated safety and efficacy in a preliminary study.

First-in-human study of the Intraluminal Gastrointestinal Stimulation Capsule

An ingestible Intraluminal Gastrointestinal Stimulation Capsule (IGSC) system designed to reduce fluid intake in obese people has demonstrated safety and efficacy in a preliminary study.

Gastric and intestinal electrical stimulation via a non-invasive, ingestible Intraluminal Gastrointestinal Stimulation Capsule (IGSC) system for treating obesity is safe, well-tolerated, and simple to use, according to a first-in-human study presented at this year’s United European Gastroenterology (UEG) week conference. 

Overweight/obese participants were monitored after ingesting the capsule to see if it reduced fluid consumption. “It’s clear that in five out of the six patients for which we have data, there’s a substantial decrease in the amount of fluid that they can intake,” said Mr. Roey Ringel, medical undergraduate studying at the University of Columbia, New York City, US, who reported the results. 

“We saw a decrease in the composite hunger-satiety score in post-treatment compared to baseline,” he added. “Also, on average, subjects drank 27% less of the nutrient drink after two IGSC system sessions as compared to their baseline. In terms of efficacy, these are exploratory preliminary results, but they offer promising indications of treatment efficacy on reducing appetite.”

The small study showed no serious adverse events, no effects on heart activity and no abnormal findings on physical examination and laboratory tests in participants.

Gastric electrical stimulation reduces appetite

The capsule is based on the premise that gastric electrical stimulation has been shown to reduce appetite, food intake and weight, thus leading to recent Food and Drug Administration (FDA) approval of a surgically implanted gastro-stimulator device for the treatment of obesity. The system delivers electrical pulses via surgically implanted electrodes on the trunks of the vagus nerve to promote weight loss by blocking vagal nerve transmission. 

“The reservation with this is that surgically or endoscopically implanting gastrointestinal stimulating devices can be unnecessarily invasive and expensive,” remarked Mr. Ringel. 

However, interest in neuromodulation and bioelectronic medicine has increased over the past few years, to the end that the National Institutes of Health (NIH) has established a specific program to support research in this area (SPARC). 

“The results of past studies support the theory that vagus nerve stimulation leads to reductions in food intake and body weight gain by increasing brain satiety signals conducted through the vagal afferents,” explained the researcher.

Electrical stimulation of the GI system via a swallowed capsule

He then introduced the novel IGSC system for the treatment of obesity. “The capsule is connected up to a control unit comprised of a fully controlled, fully programmable, non-invasive wireless system linked to a mobile phone app. A pre-clinical proof-of-concept study has shown intraluminal gastric stimulation with the system generating myoelectrical activity similar to stimulation via implanted electrodes,” he said, outlining how the system worked. 

The study aimed to examine the safety, feasibility, and signals of the efficacy of the capsule system for the treatment of obesity in humans. “Our study was based on the hypothesis that the IGSC capsule will pass without serious adverse events associated with the treatment; and that intragastric electrical stimulation via the IGSC system will be associated with reduced appetite and/or early satiety.”

The prospective seven- day, the open-label study recruited six male and female healthy volunteers, age 21 to 65 years, who were overweight and class I obese (Body Mass Index (BMI) ≥ 27 and < 35). Each subject swallowed one capsule on day four and day six of the intervention period and participants were asked to record their meal schedule and to complete designated questionnaires relating to hunger, satiety, adverse events, and any other general sensations during the treatment period. All participants underwent a nutrient drink test at baseline/end of screening (day three) and end of the intervention (day seven). Satiety and hunger sensations were recorded on a 10-point Likert scale, and an appetite score was calculated as a hunger/satiety composite. 

The nutrient drink test (using Ensure) was developed to assess gastric accommodation and meal-induced symptoms, and a test was performed in the morning after an overnight fast. “The actual volume of Ensure consumed was considered the maximum tolerated volume for that individual,” said Mr Ringel, adding that, “After completing the test, postprandial sensation of hunger, satiety and other GI symptoms were measured every 30 minutes over three hours with participants scoring symptoms of, for example, bloating and hunger.”

“Regarding safety, all capsules remained intact throughout their passage through the gastrointestinal tract, and were naturally excreted in all 12 treatment sessions,” reported Mr. Ringel. “No harmful effects were noted in any of the subjects during electrical stimulation including in electrocardiogram (ECG), heart activity monitoring during study visits, and 24-hour ambulatory Holter ECG monitoring.”

Seven adverse events (AEs) were reported, all of which were mild, short-lived and self-resolving. Nausea was experienced in four participants, migraine in two, and abdominal discomfort in one.

This study was funded by Melcap Systems.