Glucose basics
The link between gut (GI) hormones and glucose health
By Scott Urquhart, PA-C, DFAAPA
Published: May 20, 2025
4 min read
The content in this article should not be taken as medical advice. Please consult with your healthcare provider regarding your individual health needs.
Understanding how your body regulates glucose is key to maintaining metabolic health. While insulin often takes the spotlight in glucose management, it’s important to recognize the role of gut or gastrointestinal (GI) hormones in the process. These hormones help fine-tune glucose levels, manage appetite, and support digestion, working in tandem with insulin to keep everything balanced.
How your body gets glucose
Glucose is derived from the food you eat. The liver and small intestine convert dietary sugars like fructose and sucrose into glucose, while carbohydrates in food such as bread, potatoes, and rice are broken down into simpler sugars by enzymes in the mouth and small intestine before being absorbed into the bloodstream.
Glucose is the body’s primary energy source, fueling all cells, including the brain. The stored form of glucose, called glycogen, is primarily kept in the liver, where it can be easily converted back into glucose when needed.
The role of insulin and glucagon
Before discussing gut hormones, let's review two key hormones produced in the pancreas: insulin and glucagon.
Insulin
Produced by the beta cells of the pancreas, insulin is required to transport glucose from the bloodstream into the body’s cells. It works like a key, unlocking the cell so glucose can enter and be used for energy. This process helps regulate glucose levels and keeps them in a healthy range.
Glucagon
Produced by the alpha cells of the pancreas, glucagon has the opposite effect of insulin. When glucose levels drop, such as between meals, glucagon signals the liver to release stored glycogen as glucose, ensuring the brain and other organs receive energy.
While insulin and glucagon are primary regulators, GI hormones also influence glucose metabolism in significant ways.
How gut hormones affect glucose health
Several gut hormones interact with insulin and glucagon to regulate glucose levels, appetite, and digestion.
GLP-1 (Glucagon-Like Peptide-1) & GIP (Glucose-Dependent Insulinotropic Polypeptide)
GLP-1 is secreted by specialized L-cells in the small and large intestines, while GIP is secreted by K-cells in the small intestine. Both hormones are released in response to food intake, signaling the pancreas to produce insulin when glucose levels rise. In addition to promoting insulin secretion, GLP-1 also suppresses glucagon after meals and plays a role in appetite regulation, which can support glucose management and weight control.
Amylin
Amylin is produced by the beta cells in the pancreas and plays multiple roles in glucose regulation. It slows digestion, suppresses glucagon after meals, and promotes a sense of fullness, all of which help prevent sharp spikes in glucose following meals. By influencing digestion and appetite, amylin supports overall metabolic balance.
Ghrelin
Known as “the hunger hormone,” Ghrelin is primarily produced in the stomach and is known for stimulating appetite and food intake. It also impacts glucose metabolism by decreasing insulin secretion and reducing insulin sensitivity, which can contribute to higher glucose levels. Ghrelin’s role in hunger and metabolism makes it an important hormone to consider when looking at overall glucose regulation.
PYY (Peptide YY)
PYY is produced in the small intestine and colon and plays a key role in appetite suppression. After meals, it signals the brain to reduce food intake, helping to prevent overeating. While it does not directly regulate glucose, PYY contributes to metabolic health by curbing excessive carbohydrate consumption, which could otherwise lead to glucose spikes.
Other factors that can impact GI hormone regulation
Exercise and strength training
Regular strength training has been shown to positively influence the body’s natural GLP-1 release and improve insulin sensitivity, leading to stronger overall metabolic health and glucose regulation.
The gut microbiome
The gut microbiome—a distinct ecosystem of trillions of microorganisms, including bacteria, viruses, fungi, and parasites—plays a crucial role in metabolic health. A well-balanced microbiome influences the release of gut hormones like GLP-1 and GIP, supporting glucose regulation and insulin secretion. To maintain a healthy gut microbiome:
- Eat fiber-rich foods (vegetables, whole grains, legumes)
- Include lean proteins and healthy unsaturated fats
- Consume prebiotic foods (onions, garlic, bananas) and probiotic sources (yogurt, fermented foods)
- Limit processed sugars, which can disrupt gut bacteria balance
The bottom line
Gastrointestinal (GI) hormones play a vital role in glucose regulation, working alongside insulin and glucagon to maintain glucose balance, digestion, and appetite management. Understanding how these hormones function can help guide lifestyle choices, such as mindful eating, physical activity, and gut health maintenance, all of which contribute to stronger metabolic health.
By tracking your glucose response with a biosensor like Stelo, you can gain valuable insights into how your body reacts to different foods and habits. With this knowledge, you can take proactive steps toward optimizing your glucose levels and overall well-being.
The production of this article was sponsored by Stelo by Dexcom.
Author profile
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Scott Urquhart, PA-C, DFAAPA
Scott Urquhart has been practicing endocrinology since 1996 with Diabetes and Thyroid Associates in Spotsylvania, Virginia. He is a founding member and former President of the American Society of Endocrine PAs.