Probiotics

Do probiotics prevent colds?

Updated 4 Nov 2026

Short answer

They may lower the risk. A 2022 Cochrane review of 23 trials with 6950 people studied acute upper airway infections, such as colds:[1]

  • People with at least one infection: 24% fewer (low certainty).[1]
  • People with at least three infections: 41% fewer (moderate certainty).[1]
  • Length of an infection: 1.22 days shorter (low certainty).[1]
  • People who needed antibiotics for these infections: 42% fewer (moderate certainty).[1]

Most trials used one or two strains, such as Lactobacillus plantarum HEAL9 or Lactobacillus paracasei 8700:2 or N1115, for more than 3 months. These results may not apply to other strains.[2] Side effects were minor and mostly affected the gut.[1] The trial details are in the protocol Probiotics for colds.

Sources (2)

  1. Probiotics for preventing acute upper respiratory tract infections. Zhao Y, Dong BR, Hao Q Cochrane Database Syst Rev, 2022. PMID 36001877
  2. Probiotics: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2025. ods.od.nih.gov

More about probiotics

What are probiotics?Do probiotics change your gut bacteria?Is a higher CFU count better?Which foods contain probiotics?What are probiotics used for?Do probiotics prevent diarrhea from antibiotics and C. difficile?

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