Prebiotics

Are prebiotics safe?

Updated 4 Nov 2026

Short answer

Prebiotics are generally considered safe, but they can cause gas, bloating and diarrhea, more so at higher doses.[1] A 2023 Cochrane review covered 45 studies of synbiotics, prebiotics and probiotics in chronic kidney disease. Side effects were uncommon and mild, such as flatulence, nausea, diarrhea and abdominal pain, but they were poorly reported.[2]

Severe allergic reactions have been reported. A woman with an artichoke allergy had anaphylaxis, a severe allergic reaction, after foods with inulin.[3] Anaphylaxis to GOS in milk formula has been described in people with allergies in South-East Asia. A study at Singapore allergy clinics estimated that up to 3.5% of patients are allergic to one commercial GOS.[4]

No official upper limit for prebiotics was found in the NIH Office of Dietary Supplements and EFSA sources searched.[5][6] People with irritable bowel syndrome or inflammatory bowel disease, people with allergies and people who take diabetes medicine should ask a doctor or pharmacist first.[7][8][4][9]

Sources (9)

  1. Prebiotics and Probiotics for Gastrointestinal Disorders. Rau S, Gregg A, Yaceczko S, Limketkai B Nutrients, 2024. PMID 38542689
  2. Synbiotics, prebiotics and probiotics for people with chronic kidney disease. Cooper TE, Khalid R, Chan S, Craig JC, Hawley CM, Howell M, et al. Cochrane Database Syst Rev, 2023. PMID 37870148
  3. Anaphylactic reaction to inulin: first identification of specific IgEs to an inulin protein compound. Franck P, Moneret-Vautrin DA, Morisset M, Kanny G, Mégret-Gabeaux ML, Olivier JL Int Arch Allergy Immunol, 2005. PMID 15650313
  4. Anaphylaxis to galacto-oligosaccharides--an evaluation in an atopic population in Singapore. Soh JY, Huang CH, Chiang WC, Llanora GV, Lee AJ, Loh W, et al. Allergy, 2015. PMID 25951913
  5. Probiotics: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2025. ods.od.nih.gov
  6. Scientific Opinion on the substantiation of a health claim related to "native chicory inulin" and maintenance of normal defecation by increasing stool frequency. European Food Safety Authority, 2015. www.efsa.europa.eu
  7. Fermentable Carbohydrates [FODMAPs] Exacerbate Functional Gastrointestinal Symptoms in Patients With Inflammatory Bowel Disease: A Randomised, Double-blind, Placebo-controlled, Cross-over, Re-challenge Trial. Cox SR, Prince AC, Myers CE, Irving PM, Lindsay JO, Lomer MC, et al. J Crohns Colitis, 2017. PMID 28525543
  8. Colon Hypersensitivity to Distension, Rather Than Excessive Gas Production, Produces Carbohydrate-Related Symptoms in Individuals With Irritable Bowel Syndrome. Major G, Pritchard S, Murray K, Alappadan JP, Hoad CL, Marciani L, et al. Gastroenterology, 2017. PMID 27746233
  9. Inulin-type fructans supplementation improves glycemic control for the prediabetes and type 2 diabetes populations: results from a GRADE-assessed systematic review and dose-response meta-analysis of 33 randomized controlled trials. Wang L, Yang H, Huang H, Zhang C, Zuo HX, Xu P, et al. J Transl Med, 2019. PMID 31805963

More about prebiotics

What are prebiotics?Do prebiotics change your gut bacteria?How long do prebiotics take to work?Which foods contain prebiotics?What are prebiotics used for?Is a synbiotic better than a prebiotic alone?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.