by Sherri Thomas, DO
I came across an article published in December 2023 in Science(1) that shared results of an animal trial of a novel device for weight loss called the VIBES pill. I would encourage you to read the article if you want to understand the science better, but in short it was designed to be ingested prior to meals where it spends about 30-40 minutes vibrating in the stomach. This vibration stimulates the vagal nerve and helps signal satiety to the brain and end the meal earlier. In this study of 10 pigs, who are often used in GI device studies because of their similar GI anatomy to humans, it was found that the stimulation resulted in about 30% less intake at those meals, which in these growing pigs was found to limit their weight gain. They also measured blood levels of ghrelin, insulin, glucagon, c-peptide, PYY, and GLP-1 and found that by artificially signally stomach distention via the vagal nerve, VIBES induces the gastric phase metabolic response.
At first glance, if one overlooks concerns about repeatedly swallowing a large battery-operated pill that now needs to exit the body, or that it only sends a signal of fullness for an average of 38 minutes at mealtimes leaving patients to eat ad lib the rest of the day, one may be tempted to share the inventor and PI’s enthusiasm. In an article in Medical News Today(2), Dr. Srinivasan said “At scale, our device could be manufactured at a pretty cost-effective price point. I’d 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 and expensive options that are available today.” However, I can’t help but remain skeptical as they are talking about transforming care based on results from a 2-week animal study. I worry that researchers may continue to miss the big picture when it comes to the chronic diseases of overweight and obesity but focusing on the short-game and forgetting about the long-game.
It is very short-sighted when a therapy focuses primarily on weight loss, which in my opinion is the “easy” part of weight management, with little regard for maintenance of the weight loss. There are countless diets, supplements, and programs that can produce weight loss, but where so many of them consistently fail to demonstrate effectiveness is in the maintenance of weight loss phase – which is essentially the rest of the patient’s life. It’s only after patients lose about 3-5% or more of their total body weight that they start to have a decrease in satiety hormones and an increase in ghrelin resulting in symptomatic hunger, cravings and decreased satiety which is what makes patients so likely to eventually regain the weight that they have lost. What patients, practitioners, and researchers alike all need to understand is that during the first 3-5% of total body weight loss most people truly do not need more than nutritional, exercise, and behavioral intervention. This is because their body has not yet started fighting the weight loss. This short trial on pigs lasted for 2 weeks and was performed on growing pigs, so it did not even lead to weight loss only decreased weight gain compared to the control pigs.
I will of course be interested to follow along if they continue to test this technology, particularly if they move on to human trials. However, I’ll reserve phrases like “transform care” for when we have human data that demonstrates not only weight reduction, but also sustained maintenance of that weight reduction beyond a few weeks or months.
To date, there is no cure for this metabolic adaptation, only tools such as surgery and medication that help to counteract it. This is why it is no surprise that if interventions are discontinued once the weight is lost, whether they be dietary, behavioral, or medical, we see metabolic adaptation win and weight is regained. Understanding this, it begs the question – is there a point to developing anti-obesity therapies that aren’t meant to be continued indefinitely? Sure, it’s nice when an intervention makes the weight loss phase “easier” or more rapid, but where we really need interventions to shine is in blunting or counteracting the body’s response to weight loss so that this is the last time the patient loses the weight.
While it will always be helpful to have multiple tools in the obesity management toolbox to choose from (and even mix and match), I would not be surprised if in the future we find that short-term therapies have a very limited space in the toolbox, if they have a space at all.
1. Shriya S. Srinivasan et al. A vibrating ingestible bioelectronic stimulator modulates gastric stretch receptors for illusory satiety.Sci. Adv.9,eadj3003(2023).
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