As Global Prebiotics Week unfolds, it offers a timely opportunity to spotlight the growing body of research around prebiotics – non-digestible food components that nourish beneficial microbes in the gut. Unlike probiotics, which introduce live microorganisms into the digestive system, prebiotics serve as fuel for the bacteria already residing there, helping them thrive and support key physiological functions.

The Global Prebiotic Association defines a prebiotic as “a product or ingredient that is utilized by the microbiota, producing a health or performance benefit.” This distinction is important: while probiotics are often strain-specific and sensitive to environmental conditions, prebiotics are more stable and can be incorporated into a wide range of foods and supplements.

How prebiotics work

Prebiotics are typically complex carbohydrates – such as inulin, fructo-oligosaccharides (FOS), and galacto-oligosaccharides (GOS) – that resist digestion in the upper gastrointestinal tract. Once they reach the colon, they are fermented by resident microbes, producing short-chain fatty acids (SCFAs) like butyrate, acetate, and propionate. These SCFAs play a role in maintaining gut barrier integrity, modulating inflammation, and supporting metabolic health¹.

Emerging evidence suggests that prebiotics may influence not only digestive function but also immune regulation, mood, and even cognitive performance through the gut-brain axis². For example, SCFAs have been shown to interact with immune cells and influence cytokine production, potentially impacting systemic inflammation³.

Prebiotics vs. probiotics

While both prebiotics and probiotics contribute to gut health, they operate through different mechanisms. Probiotics are live organisms that may colonize the gut temporarily, whereas prebiotics selectively stimulate the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus⁴. Products that combine both are referred to as synbiotics, aiming to deliver a synergistic effect⁵.

Sources of prebiotics

Prebiotics are found naturally in a variety of plant-based foods. Common sources include:

• Chicory root
• Garlic
• Onions
• Leeks
• Asparagus
• Bananas
• Whole grains
• Raw oats

Functional ingredients like acacia fiber are also gaining attention for their fermentability and ability to modulate gut microbiota composition⁶.

[Read more about top foods for gut health]

Why it matters

The human gut microbiome is increasingly recognized as a central player in health and disease. Disruptions to microbial balance – whether through diet, stress, or antibiotics – can have wide-ranging effects. Supporting the microbiome with prebiotics may offer a proactive strategy for maintaining digestive and systemic health.

Global Prebiotics Week encourages individuals, healthcare professionals, and industry stakeholders to explore the science, share resources, and make informed dietary choices. Whether through food or supplementation, integrating prebiotics into daily routines may be a simple yet impactful way to support long-term wellbeing.

This information is provided for educational purposes only and is not a substitute for professional medical advice. Always seek the guidance of your physician or qualified healthcare provider with any questions you may have regarding your health or a medical condition.

References

1. Rowland I, Gibson G, Heinken A, et al. Gut microbiota functions: metabolism of nutrients and other food components. Eur J Nutr. 2018;57(1):1-24. doi:10.1007/s00394-017-1445-8
2. Robinson JM, Breed MF. Green prescriptions and mental health: a review of evidence and potential pathways. Front Psychol. 2021;12:768948. doi:10.3389/fpsyg.2021.768948
3. Wang Y, Florez ID, Morgan RL, et al. Probiotics, prebiotics, lactoferrin, and combination products for prevention of mortality and morbidity in preterm infants: a systematic review and network meta-analysis. JAMA Pediatr. 2023;177(11):1129–1131. doi:10.1001/jamapediatrics.2023.3856
4. Office of Dietary Supplements. Probiotics – Health Professional Fact Sheet. National Institutes of Health. Available from: https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional
5. NCCIH. Probiotics: Usefulness and Safety. National Center for Complementary and Integrative Health. Available from: https://www.nccih.nih.gov/health/probiotics-usefulness-and-safety
6. Global Prebiotic Association. Global Prebiotics Week. Available from: https://prebioticassociation.org/global-prebiotics-week