PrebioticsDo prebiotics prevent infections?
Updated 4 Nov 2026
Short answer
Possibly in infants and children, and less clearly in adults. For immune support, a 2022 review found fewer people with a respiratory infection across 17 prebiotic trials (odds ratio 0.73). Most trials were in infants and children, and evidence in adults was thinner.[1] A 2026 review of healthy people also found fewer infections in infants given GOS, FOS or 2'-fucosyllactose.[2]
In one trial of 142 hospital patients treated for Clostridium difficile diarrhea, relapse was 8.3% with oligofructose against 34.3% with placebo.[3] This result comes from a single trial. For traveler's diarrhea, a 2017 guideline found the evidence insufficient.[4]
Sources (4)
- The Effects of Prebiotics, Synbiotics, and Short-Chain Fatty Acids on Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis. Williams LM, Stoodley IL, Berthon BS, Wood LG Adv Nutr, 2022. PMID 34543378
- Impact of non-digestible carbohydrates and prebiotics on immunity, infections, inflammation and vaccine responses: a systematic review of evidence in healthy humans and a discussion of mechanistic proposals. Arioz Tunc H, Calder PC, Cait A, Dodd GF, Gasaly Retamal NYI, Guillemet D, et al. Crit Rev Food Sci Nutr, 2026. PMID 40516031
- Effect of the prebiotic oligofructose on relapse of Clostridium difficile-associated diarrhea: a randomized, controlled study. Lewis S, Burmeister S, Brazier J Clin Gastroenterol Hepatol, 2005. PMID 15880313
- Probiotics: Usefulness and Safety. NIH National Center for Complementary and Integrative Health, 2019. www.nccih.nih.gov
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.