Scientists at the Massachusetts Institute of Technology (MIT) have devised a groundbreaking approach to harness the signals sent from the stomach to the brain during a meal. Their method involves an ingestible capsule that vibrates within the stomach, activating stretch receptors to create a perceived sense of fullness.
Published in “Scientific Advances,” the team’s research demonstrates that animals administered with this capsule 20 minutes before eating experienced a 40% reduction in food intake. This stimulation not only triggered the release of satiety hormones but also presented a potential minimally invasive solution for treating obesity.
Dr. Shriya Srinivasan, the lead author and former MIT graduate now an assistant professor of bioengineering at Harvard University, envisions this capsule as a compelling option for those seeking weight loss or appetite control. The technology offers a promising alternative with minimized side effects compared to conventional pharmaceutical treatments.
Satiety Mechanism and Capsule Design
The specialized cells known as mechanoreceptors sense the stretching of the stomach when it expands, signaling the brain through the vagus nerve. This triggers the release of hormones like insulin, C-peptide, Pyy, and GLP-1, collectively aiding digestion, inducing satiety, and signaling the cessation of eating.
Dr. Srinivasan’s interest in controlling this process through vibrations arose during her time at MIT, exploring artificial stretching of stomach mechanoreceptors. Collaborating with Dr. Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital, the researchers developed a capsule with a vibration component, approximately the size of various vitamins.
Powered by a small silver oxide battery, the capsule dissolves its gelatinous coating upon reaching the stomach, activating the vibration motor through an electronic circuit. Animal studies demonstrated that the activated capsule stimulated mechanoreceptors, sending signals to the brain via the vagus nerve, mimicking the post-meal hormone release pattern.
Behavioral Changes and Future Prospects
The researchers observed a profound behavioral change in animals treated with the vibrating capsule, showcasing the potential of leveraging the endogenous system for therapeutic benefits. Dr. Traverso emphasized the possibility of overcoming challenges and costs associated with biologic drug delivery by modulating the intestinal nervous system.
The current version of the capsule vibrates for approximately 30 minutes upon reaching the stomach, but researchers plan to explore options for extended stay within the stomach, allowing wireless on/off control as needed. Animal studies demonstrated that the capsule passed through the digestive tract within four to five days without adverse effects.
This novel capsule presents an alternative for treating obesity, especially when non-medical interventions like diet and exercise prove ineffective, and invasive medical interventions become impractical. The researchers believe that the cost-effectiveness of manufacturing these capsules could make them accessible to a broader population.
The team is now exploring methods to scale up capsule production for human clinical trials, crucial for evaluating safety, determining optimal timing for pre-meal ingestion, and establishing dosing frequency.
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