What are GLP-1 medications?
Weight loss medications, such as Ozempic, Wegovy, and Mounjaro, are a type of drug originally designed to help people with type 2 diabetes manage their blood sugar1,4. However, they have recently gained attention for their ability to support weight loss.
These medications work by mimicking a natural gut hormone called glucagon-like peptide-1 (GLP-1), which helps control blood sugar levels2, slow down digestion, and reduce appetite3. This means people feel fuller for longer and eat less, leading to weight loss.
Why has Ozempic become so popular?
Highly Effective for Weight Loss – Clinical trials have shown that GLP-1 RAs can lead to significant and sustained weight loss5, making them a breakthrough in obesity treatment.
Appetite Suppression – These drugs reduce hunger and cravings6, helping individuals consume fewer calories.
Celebrity & Media Attention – Widespread media coverage and endorsements from high-profile figures have contributed to their popularity.
Obesity as a Medical Condition – More healthcare professionals now recognize obesity as a chronic disease requiring medical intervention rather than just lifestyle changes.
Probiotics can help to alleviate GI side effects of weight loss drugs
Common GI side effects of GLP-1 medications
Despite their effectiveness, GLP-1 RAs often cause gastrointestinal side effects7,8, especially during the initial weeks of treatment as the body adjusts:
Nausea & Vomiting – Due to slower stomach emptying, food stays in the stomach longer, leading to feelings of fullness and nausea.
Diarrhea – Increased gut motility and changes in digestion may lead to loose stools.
Constipation – Slower intestinal movement can result in constipation for some individuals9.
Abdominal Pain & Bloating – Changes in digestion and gut microbiota can cause discomfort and bloating.
These side effects can impact adherence to the medication, leading some people to discontinue treatment10. However, probiotics may offer a way to support the gut and alleviate these symptoms, improving tolerance to GLP-1 RAs.
The role of the gut microbiome in GI health
The gut microbiome, comprising trillions of microorganisms, plays a crucial role in digestion, nutrient absorption, and immune function11,12. Disruptions in this microbial balance can lead to GI symptoms.
Probiotics - live beneficial bacteria - can help restore and maintain a healthy gut microbiome. They exert positive effects by:
Enhancing Digestive Function: Aiding in the breakdown of food substances.
Modulating Immune Responses: Reducing inflammation and promoting immune tolerance.
Inhibiting Pathogenic Bacteria: Competing with harmful microbes for resources and adhesion sites.
Probiotics for managing GLP-1 medication side effects
Research indicates that specific probiotic strains may alleviate GI side effects associated with GLP-1 RAs:
Diarrhea: Saccharomyces boulardii has demonstrated efficacy in reducing antibiotic-associated diarrhea13 and may help manage diarrhea induced by GLP-1 RAs.
Constipation: Bifidobacterium lactis BB-12® has been shown to improve bowel regularity and stool consistency14, potentially counteracting constipation.
Abdominal Pain and Bloating: Lactobacillus acidophilus NCFM® and Bifidobacterium lactis Bi-07® have been associated with reductions in abdominal discomfort and bloating in individuals with irritable bowel syndrome (IBS)15.
Health Professionals can read about these probiotic strains on our Probiotic Database.
How to use probiotics alongside weight loss medications
To maximise benefits and minimise potential interactions:
Consult Healthcare Providers: Before starting probiotics, discuss with a healthcare professional, especially if you have underlying health conditions or are on multiple medications.
Select Appropriate Strains: Choose probiotics with strains supported by clinical evidence for specific symptoms.
Monitor for Side Effects: While probiotics are generally safe, monitor for any adverse reactions and report them to your healthcare provider.
Key takeaway
Specific probiotic strains such as Saccharomyces boulardii and Bifidobacterium lactis BB-12® can offer a supportive approach to managing GI side effects associated with GLP-1 receptor agonists. Ongoing research continues to elucidate the full extent of these benefits, underscoring the importance of personalised medical advice in treatment planning.
You may also wish to read our related articles:
Probiotics and Antibiotic-Associated Diarrhoea
References
MacDonald, P. E. et al. The multiple actions of GLP-1 on the process of glucose-stimulated insulin secretion. Diabetes 51, S434–442 (2002).
Bu, T. et al. Glucagon-like peptide-1: New regulator in lipid metabolism. Diab Metab. J. 48, 354–372 (2024).
Andreasen, C. R., Andersen, A., Knop, F. K. & Vilsbøll, T. How glucagon-like peptide 1 receptor agonists work. Endocr. Connect 10, R200–r212 (2021).
Blevins, T. et al. DURATION-5: Exenatide once weekly resulted in greater improvements in glycemic control compared with exenatide twice daily in patients with type 2 diabetes. J. Clin. Endocrinol. Metab. 96, 1301–1310 (2011).
O’Neil, P. M. et al. Efficacy and safety of semaglutide compared with liraglutide and placebo for weight loss in patients with obesity: a randomised, double-blind, placebo and active controlled, dose-ranging, phase 2 trial. Lancet 392, 637–649 (2018).
Moon, S. et al. Efficacy and safety of the new appetite suppressant, liraglutide: A meta-analysis of randomized controlled trials. Endocrinol. Metab. (Seoul.) 36, 647–660 (2021).
Ghusn W, Hurtado M (2024) Glucagon-like Receptor-1 agonists for obesity: Weight loss outcomes, tolerability, side effects, and risks. Obesity Pillars, 12: 100127
Bettge K, Kahle M, Abd El Aziz MS, et al. Occurrence of nausea, vomiting and diarrhoea reported as adverse events in clinical trials studying glucagon-like peptide-1 receptor agonists: a systematic analysis of published clinical trials. Diabetes Obes Metab. 2017;19(3):336–347.
Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989.