How GLP-1 Medications Work - and Why Your Gut Needs Support

GLP-1 receptor agonists, like Wegovy®, Ozempic®, and Mounjaro®, are powerful medications that help people lose weight and improve metabolic health. But to get the most out of these therapies, your gut needs support, especially at the beginning. Because GLP-1s slow digestion, you may still experience gastrointestinal side effects, even if you are following a healthy diet. 

In this article, we explore the science behind how GLP-1s work, the key mechanisms that drive weight loss , and why gut health support like Forte80™ makes a real difference.

Appetite Suppression: The Main Driver

GLP-1s act on the brain’s appetite centres, reducing hunger and increasing the feeling of fullness.

• The majority of GLP-1-induced weight loss is attributed to reduced food intake due to appetite suppression.
• Clinical trials show that people on semaglutide eat significantly fewer calories than those on placebo. [1]

Delayed Gastric Emptying: A Complementary Role

One of the ways GLP-1 medications help reduce weight is by slowing how quickly food leaves the stomach. This delay increases feelings of fullness, helps control post-meal blood sugar, and reduces the desire to eat again soon. 

• Delayed gastric emptying plays a contributory role in GLP-1-related weight loss, particularly during the initial weeks of treatment, but appetite suppression remains the primary mechanism.
• It is especially relevant in the early weeks of treatment, before the stomach adapts. [2]
  

But this mechanism also leads to gastrointestinal side effects, including:

• Bloating and early satiety – a feeling of fullness sooner than expected when eating.
• Constipation – commonly reported across compounds and clinical studies.
  
• Nausea – one of the most frequently observed effects, especially during dose increases.
  
• Abdominal cramping or reflux – often triggered by large or high-fat meals. [3]

These digestive side effects are a top reason why people stop GLP-1 medications.

Changing Food Preferences: Helping You Choose Better

GLP-1s also affect brain regions related to reward and taste. Studies show people:

• Eat fewer high-fat and high-sugar foods.
• Prefer more protein- and fibre-rich meals. [4]
  

This supports healthier eating, while shifting the composition and variety of your diet, which may temporarily alter gut function and microbiota activity. 

Gut Microbiome: The Overlooked Link

GLP-1 receptor agonists work primarily by acting on the brain and gut to curb appetite and slow digestion. This can indirectly affect the gut microbiome, as a reduced appetite often leads to eating less overall, including less fibre. Since fibre and fermented plant foods are key to feeding beneficial gut bacteria, this drop in intake may lead to a temporary imbalance, known as dysbiosis.

The result? Sluggish digestion, changes in gut function, or mild inflammation until the diet settles and the gut adjusts.

Dysbiosis refers to an imbalance in the gut microbiome. A healthy microbiome supports digestion, immune function, appetite control, and even mental well-being. But in many people with obesity, this balance is disrupted.

Studies show that individuals with obesity often have reduced microbial diversity, fewer beneficial bacteria, and higher levels of inflammation-promoting microbes. [5]

What causes dysbiosis?

• Poor diet (low fiber, high sugar and fat).
• Chronic low-grade inflammation.
• Metabolic stress and hormonal changes.
• Reduced microbial exposure and diversity. [6]

This microbial imbalance can worsen digestive issues, impair blood sugar control, and make it harder to lose weight even on GLP-1 medications. That is why gut support, like Forte80™, is especially important for people on a weight loss journey.

Dietary Change Is Powerful - but Also Disruptive

GLP-1 receptor agonists often help users to make healthier food choices, but they also reduce overall appetite. Side effects like nausea and early fullness can further lower food intake, making it harder to include key gut-friendly foods like fibre, whole grains, fermented foods, and nutrient-rich vegetables.

Even with good intentions, this shift in eating habits can disrupt gut balance, particularly during the first one to three months of treatment. 

That is why gut health support is not optional. It should be a priority.

Forte80™: The Right Gut Support at the Right Time

Forte80™ is a high-strength, clinically designed probiotic created for consumers using GLP-1s. Each daily dose delivers:

• 80 billion CFUs. 
• 4 scientifically selected probiotic strains.
• Formulated for gut resilience during weight loss.

Forte80™ Supports:

• Less nausea, bloating, cramping, and constipation.
• More balanced gut flora, even when food intake drops.
• Better comfort, so you can stay consistent with your GLP-1 and weight loss plan.

Final Thought: GLP-1 Success Is Not  Just About the Injection or the Pill

GLP-1s work primarily by suppressing appetite. They also slow digestion, shift food preferences, and indirectly influence the gut microbiome.

However, these dietary changes, eating less overall, consuming less fibre, and adjusting long-standing habits, can place added stress on the gut.

That is where Forte80™ makes a difference, helping your digestion adapt, reducing symptoms, and supporting long-term success.

1.    Aldawsari, H., et al. The efficacy of GLP-1 analogues on appetite parameters, gastric emptying, taste sensitivity, and food preferences among adults with obesity: A systematic review of randomized clinical trials. Nutrients. 2023.
2.    Moiz, A., et al. Mechanisms of GLP-1 Receptor Agonist-Induced Weight Loss: A Review of Central and Peripheral Pathways in Appetite and Energy Regulation. Obesity Reviews. 2025.
3.    Gorgojo-Martínez, J. J., et al. Clinical Recommendations to Manage Gastrointestinal Adverse Events in Patients Treated with GLP-1 Receptor Agonists: A Multidisciplinary Expert Consensus. Journal of Clinical Medicine. 2022.
4.    Eren-Yazicioglu, C. Y., et al. Can GLP-1 Be a Target for Reward System Related Disorders? A Qualitative Synthesis and Systematic Review Analysis of Studies on Palatable Food, Drugs of Abuse, and Alcohol. Frontiers in Behavioral Neuroscience. 2021.
5.    Le Chatelier, E., et al. Richness of human gut microbiome correlates with metabolic markers. Nature. 2013;500(7464):541-6.
6.    Hrncir, T. Gut Microbiota Dysbiosis: Triggers, Consequences, Diagnostic and Therapeutic Options. Microorganisms. 2022.