1 hr 10 min
Geeking Out on Bile, Bugs, and Bariatric Surgery with Randy Seeley, PhD Weight Loss Surgery Podcast - Bariatric / Lap Band / RYGB / Gastric Bypass / Vertical Sleeve Gastrectomy
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- Health & Fitness
In this episode I bring you obesity and bariatric surgery research scientists, Dr. Randy Seeley. If you have been a longtime listener of the podcast then you will likely remember Dr Seeley from Episode 34 where he helped us understand the theory of Set-point for body fat mass and Episode 56 where we did a deeper dive into the biology of body weight.
This time I bring Dr Seeley back to help get us get up to speed on what research has learned about bile acid metabolism in general and as it relates to obesity and bariatric surgery specifically. We also talk some about the “bugs” of the gut, also known as the gut microbiome. Additionally, we chat about what his research is revealing about sleep apnea and the gut, as well as iron metabolism after bariatric surgery. And just for fun, there is a cameo appearance of his dog, Ziggy.
After all that, as always, I share with you my concluding thoughts about the episode.
But before I cut to the episode I want to tell you about the sponsors who make this podcast possible. That would be you, my listeners. You support the podcast every time you tell someone about it, share it, rate it, and if you are able, by becoming a patron. You can become a patron of the podcast at either Patreon or PayPal where you have the option of offering either recurring monthly support or one time support. Click on Patreon or PayPal to be taken to their sites or you can find the links in the upper right-hand corner of my website, WeightLossSurgeryPodcast.com If you are already a supporter of the podcast in any capacity, thank you ever so much.
Discussed In This Episode:
Randy Seeley, PhD is a Professor of Surgery, Internal Medicine, and Nutritional Science at the University of Michigan.
One area his research focuses on is trying to find and understand the molecular signals that come from the gut in general and how bariatric surgery changes those signals to support a reduction in hunger and weight.
What is Bile: Made in the liver and stored in the gallbladder. When we eat foods with lipids (fat). Bile is released at the beginning of the small intestines. Unused bile acids are reabsorbed into the blood at the bottom part of the small intestine and are brought back up to the liver to be used again.
Roux-en-Y Gastric Bypass (RYGB) patients have higher levels of bile circulating in their blood compared to non-RYGB patients.
Interestingly, animal models and humans who undergo Vertical Sleeve Gastrectomy (VSG) also have increased blood levels of bile, even though the intestines are not changed in VSG, only the stomach is changed. The reason is that the liver stops taking up, recycling, as much bile. Somehow the liver knows that part of the stomach has been removed.
Figuring out if this matters, led Dr Seeley to dig deeper into the role of bile acids. It turns out that bile acids not only work to break down dietary fats that are eaten. Bile also acts a Hormone (A hormone is a chemical signal that is released in one area of the body and communicates with another part of the body by binding with a receptor.) One of the important receptors that bile binds to is FXR. FXR has been linked to many aspects of metabolism.
In order to determine what role FXR plays in the binding of bile, Dr Seeley’s lab created genetically alerted rodents who no longer have the FXR receptor. They then performed VSG on the rodents. The theory was that if elevated plasma bile acids (bile in the blood) mattered to why the surgery works, then you would expect that animals who no longer have the FXR receptor would not respond as well to the surgery. That is exactly what happened. Ultimately, the animals without FXR did not have suppression of food intake even though it has a smaller stomach. Additionally, the FXR-missing animals did not have blood glucose level improvement.
Why does this matter? Dr Seeley argues the more we can identify these specific molecular pathways by which bariatric surgery works the better we can understan
In this episode I bring you obesity and bariatric surgery research scientists, Dr. Randy Seeley. If you have been a longtime listener of the podcast then you will likely remember Dr Seeley from Episode 34 where he helped us understand the theory of Set-point for body fat mass and Episode 56 where we did a deeper dive into the biology of body weight.
This time I bring Dr Seeley back to help get us get up to speed on what research has learned about bile acid metabolism in general and as it relates to obesity and bariatric surgery specifically. We also talk some about the “bugs” of the gut, also known as the gut microbiome. Additionally, we chat about what his research is revealing about sleep apnea and the gut, as well as iron metabolism after bariatric surgery. And just for fun, there is a cameo appearance of his dog, Ziggy.
After all that, as always, I share with you my concluding thoughts about the episode.
But before I cut to the episode I want to tell you about the sponsors who make this podcast possible. That would be you, my listeners. You support the podcast every time you tell someone about it, share it, rate it, and if you are able, by becoming a patron. You can become a patron of the podcast at either Patreon or PayPal where you have the option of offering either recurring monthly support or one time support. Click on Patreon or PayPal to be taken to their sites or you can find the links in the upper right-hand corner of my website, WeightLossSurgeryPodcast.com If you are already a supporter of the podcast in any capacity, thank you ever so much.
Discussed In This Episode:
Randy Seeley, PhD is a Professor of Surgery, Internal Medicine, and Nutritional Science at the University of Michigan.
One area his research focuses on is trying to find and understand the molecular signals that come from the gut in general and how bariatric surgery changes those signals to support a reduction in hunger and weight.
What is Bile: Made in the liver and stored in the gallbladder. When we eat foods with lipids (fat). Bile is released at the beginning of the small intestines. Unused bile acids are reabsorbed into the blood at the bottom part of the small intestine and are brought back up to the liver to be used again.
Roux-en-Y Gastric Bypass (RYGB) patients have higher levels of bile circulating in their blood compared to non-RYGB patients.
Interestingly, animal models and humans who undergo Vertical Sleeve Gastrectomy (VSG) also have increased blood levels of bile, even though the intestines are not changed in VSG, only the stomach is changed. The reason is that the liver stops taking up, recycling, as much bile. Somehow the liver knows that part of the stomach has been removed.
Figuring out if this matters, led Dr Seeley to dig deeper into the role of bile acids. It turns out that bile acids not only work to break down dietary fats that are eaten. Bile also acts a Hormone (A hormone is a chemical signal that is released in one area of the body and communicates with another part of the body by binding with a receptor.) One of the important receptors that bile binds to is FXR. FXR has been linked to many aspects of metabolism.
In order to determine what role FXR plays in the binding of bile, Dr Seeley’s lab created genetically alerted rodents who no longer have the FXR receptor. They then performed VSG on the rodents. The theory was that if elevated plasma bile acids (bile in the blood) mattered to why the surgery works, then you would expect that animals who no longer have the FXR receptor would not respond as well to the surgery. That is exactly what happened. Ultimately, the animals without FXR did not have suppression of food intake even though it has a smaller stomach. Additionally, the FXR-missing animals did not have blood glucose level improvement.
Why does this matter? Dr Seeley argues the more we can identify these specific molecular pathways by which bariatric surgery works the better we can understan
1 hr 10 min