[ad_1]
MIT engineers have developed an ingestible capsule that vibrates in the stomach, simulating fullness by activating stretch receptors, which in animal studies reduced food intake by about 40%. This non-invasive approach, potentially useful for weight management, is considered a cost-effective alternative to current obesity treatments.
Swallowing the device before eating can induce a feeling of satiety, tricking the brain into thinking it’s time to stop eating.
When you eat a large meal, your stomach sends signals to your brain that create a feeling of fullness, which helps you realize it’s time to stop eating. A stomach full of fluid can also send these messages, which is why dieters are often advised to drink a glass of water before eating.
M.I.T. Engineers have now devised a new way to take advantage of that phenomenon, using an ingestible capsule that vibrates inside the stomach. These vibrations activate the same stretch receptors that detect when the stomach is distended, creating an illusory feeling of fullness.
In animals that received this pill 20 minutes before eating, the researchers found that this treatment not only stimulated the release of hormones that signal satiety, but also reduced the animals’ food intake by approximately 40 percent. Scientists have much more to learn about the mechanisms that influence human body weight, but if more research suggests this technology could be used safely in humans, such a pill could offer a minimally invasive way to treat obesity. say the researchers.
“For someone who wants to lose weight or control their appetite, they could take it before every meal,” says Shriya Srinivasan PhD ’20, a former MIT graduate student and postdoc who is now an assistant professor of bioengineering at Harvard University. “This could be really interesting because it would provide an option that could minimize the side effects that we see with other drug treatments that are out there.”
Srinivasan is the lead author of the new study, which appears today in Scientific advances. Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital, is the paper’s senior author.
A feeling of fullness
When the stomach distends, specialized cells called mechanoreceptors detect this stretch and send signals to the brain through the vagus nerve. As a result, the brain stimulates the production of insulin, as well as hormones such as C-peptide, Pyy and GLP-1. All of these hormones work together to help people digest food, feel full, and stop eating. At the same time, levels of ghrelin, a hormone that promotes hunger, decrease.
While a graduate student at MIT, Srinivasan became interested in the idea of controlling this process by artificially stretching the mechanoreceptors that line the stomach, using vibrations. Previous research has shown that vibration applied to a muscle can induce the sensation that the muscle has been stretched more than it has actually been stretched.
“I was wondering if we could activate the stretch receptors in the stomach by vibrating them and making them perceive that the entire stomach has expanded, to create an illusory sensation of distention that could modulate hormones and eating patterns,” Srinivasan says.
As a postdoc at MIT’s Koch Institute for Integrative Cancer Research, Srinivasan worked closely with the Traverso lab, which has developed many novel approaches to oral drug delivery and electronic devices. For this study, Srinivasan, Traverso and a team of researchers designed a capsule the size of a multivitamin, which includes a vibrating element. When the pill, which is powered by a small silver oxide battery, reaches the stomach, acidic gastric fluids dissolve a gelatinous membrane that lines the capsule, completing the electronic circuit that activates the vibrating motor.
MIT engineers designed an ingestible capsule that vibrates inside the stomach. These vibrations activate the same stretch receptors that detect when the stomach is distended, creating an illusory feeling of fullness and reducing appetite. Such a pill could offer a minimally invasive and cost-effective way to treat obesity. Credit: Courtesy of Shriya Srinivasan, Giovanni Traverso, MIT News
In an animal study, researchers showed that once the pill starts vibrating, it activates mechanoreceptors, which send signals to the brain by stimulating the vagus nerve. The researchers tracked hormone levels during periods when the device vibrated and found that they mirrored hormone release patterns seen after a meal, even when the animals had fasted.
The researchers then tested the effects of this stimulation on the animals’ appetite. They found that when the pill was activated for about 20 minutes, before the animals were offered food, they consumed 40 percent less, on average, than when the pill was not activated. The animals also gained weight more slowly during the periods when they were treated with the vibrating pill.
“The behavior change is profound and is about using the endogenous system instead of any exogenous therapy. “We have the potential to overcome some of the challenges and costs associated with biologic drug delivery by modulating the enteric nervous system,” says Traverso.
The current version of the pill is designed to vibrate for about 30 minutes after reaching the stomach, but researchers plan to explore the possibility of adapting it to stay in the stomach for longer periods of time, where it could be turned on and off. wirelessly as needed. In animal studies, the pills passed through the digestive tract in four to five days.
The study also found that the animals did not show any signs of obstruction, perforation or other negative impacts while the pill was in their digestive tract.
An alternative approach
According to the researchers, this type of pill could offer an alternative to current approaches to treating obesity. Non-medical interventions, such as diet and exercise, do not always work and many existing medical interventions are quite invasive. These include gastric bypass surgery as well as gastric balloons, which are no longer widely used in the United States for safety reasons.
Medications such as GLP-1 agonists can also help with weight loss, but most of them must be injected and are unaffordable for many people. According to Srinivasan, the MIT capsules could be manufactured at a cost that would make them available to people who do not have access to more expensive treatment options.
“For many populations, some of the most effective therapies for obesity are very expensive. At scale, our device could be manufactured at a fairly cost-effective price,” he says. “I would love to see how this would transform care and therapy for people in global health settings who may not have access to some of the more sophisticated or expensive options that are available today.”
The researchers now plan to explore ways to scale up manufacturing of the capsules, which could allow for clinical trials in humans. Such studies would be important to learn more about the safety of the devices, as well as to determine the best time to swallow the capsule before a meal and how often it would need to be administered.
Reference: “A vibrating ingestible bioelectronic stimulator modulates gastric stretch receptors for illusory satiety” by Shriya S. Srinivasan, Amro Alshareef, Alexandria Hwang, Ceara Byrne, Johannes Kuosmanen, Keiko Ishida, Joshua Jenkins, Sabrina Liu, Wiam Abdalla Mohammed Madani , Alison M Hayward, Niora Fabian and Giovanni Traverso, December 22, 2023, Scientific advances.
DOI: 10.1126/sciadv.adj3003
Other authors of the paper include Amro Alshareef, Alexandria Hwang, Ceara Byrne, Johannes Kuosmann, Keiko Ishida, Joshua Jenkins, Sabrina Liu, Wiam Abdalla Mohammed Madani, Alison Hayward and Niora Fabian.
The research was funded by the National Institutes of HealthNovo Nordisk, the MIT Department of Mechanical Engineering, a Schmidt Scientific Fellowship, and the National Science Foundation.