When it comes to weight management and bariatric surgery success, what’s happening in your gut matters more than you might think. Your digestive system is home to trillions of bacteria—collectively known as the gut microbiome—that play a major role in metabolism, inflammation, appetite regulation, and nutrient absorption. The gut isn’t just where digestion happens—it’s a key player in your weight loss journey. That’s where prebiotics, probiotics, and postbiotics come in. What Are Prebiotics? Prebiotics are a type of fiber that feeds the good bacteria in your gut. Think of them as fertilizer for the beneficial microorganisms living in your digestive tract. Common sources: Onions, garlic, leeks Asparagus, bananas, apples, berries, oats Chicory root, Jerusalem artichokes Supplements like inulin, wheat dextrin, acacia gum, and Sunfiber® How prebiotics help: Improve insulin sensitivity and help regulate blood sugar1 Increase the production of beneficial gut bacteria2 Promote feelings of fullness by supporting the production of satiety hormones like GLP-13 May help reduce inflammation linked to obesity1 Best time to use: Pre-op patients can benefit from increasing prebiotic intake to optimize gut health before surgery.4 Post-op (after the initial healing phase), slowly reintroducing fiber and prebiotics can support long-term weight management and digestive health.3 What Are Probiotics? Probiotics are live bacteria that offer health benefits and help balance the microorganisms in your gut. They’re found in both fermented foods and supplements. Sources include: Yogurt (with live cultures), kefir Sauerkraut, kimchi, miso, tempeh Probiotic supplements (look for strains like em>Lactobacillus, Bifidobacterium) How probiotics help: Reduce gut inflammation and improve nutrient absorption1 Support the gut-brain axis to help regulate mood and appetite3 Decrease fat storage and improve metabolic health for weight management (only certain strains)4 Promote healing and reduce post-surgery GI side effects, such as diarrhea or constipation1 Best time to use: Pre-op: Supporting gut diversity before surgery can make the body more resilient.4 Post-op: Probiotics may help restore gut balance, especially after taking antibiotics or during periods of gastrointestinal discomfort.1 Tip: Always consult your bariatric team before starting a probiotic supplement, especially early post-op. What Are Postbiotics? Postbiotics are beneficial compounds produced when probiotics (beneficial bacteria) break down prebiotics (fiber-rich foods). These include short-chain fatty acids (like butyrate), enzymes, peptides, and vitamins. Although still an emerging field, postbiotics are showing great promise. How postbiotics help: Improve gut barrier function and reduce inflammation2 Help regulate blood sugar and improve insulin sensitivity3 Enhance fat metabolism3 May support immune health and reduce complications after surgery2 Best time to use: Post-op: Your body produces postbiotics naturally when you're eating prebiotic-rich foods and taking in healthy probiotics. However, postbiotic supplements may also become more widely available and useful for long-term gut health.* Maintenance phase: Supporting gut health with prebiotics and probiotics ensures a steady supply of beneficial postbiotics.2 Why It Matters for Bariatric Patients After bariatric surgery, the structure of your GI tract changes, which impacts your microbiome. Several studies have found that:1,3,4 Bariatric surgery alters gut bacteria significantly, which can enhance or hinder weight loss depending on the microbial balance. A healthier gut environment is associated with better appetite control, improved glucose metabolism, and lower inflammation—all key for long-term success. Gut imbalance (dysbiosis) can contribute to post-op issues like bloating, constipation, nutrient deficiencies, or even weight regain. Supporting your gut at every stage—before and after surgery—can help you feel better, lose weight more effectively, and avoid common digestive hurdles. Bottom Line: How to Support Your Gut for Weight Loss Eat more fiber-rich prebiotic foods (as tolerated). Incorporate fermented foods or a high-quality probiotic supplement. Support overall gut health through hydration, stress reduction, and consistent nutrition. Ask your bariatric team about incorporating these into your plan, especially if you’re experiencing GI discomfort or weight loss stalls. References 1. Kobyliak N et al. Nutr Metab (Lond). 2016;13:14. 2. Salminen S et al. Nat Rev Gastroenterol Hepatol. 2021;18(9):649-667. 3. Everard A et al. Rev Endocr Metab Disord. 2014;15(3):189-196. 4. Furet JP et al. Diabetes. 2010;59(12):3049–3057.