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Can I take probiotics with antibiotics?

Usually yes, unless you are seriously ill or your immune system is weak. Taking probiotics during antibiotics is documented in drug-level studies: in 40 trials with 13,419 people, antibiotic-related diarrhea affected 23% of those given probiotics and 27.4% of those who weren't. No source sets how many hours apart to take them. In hospital, or with a weak immune system, check with your prescriber or pharmacist before starting one.

How well documented: Documented in drug-level studies. Studies in people measured the effect directly: the medicine’s blood levels or its effect, or a test result.

Last reviewed

How we grade evidenceEditorial policy

What's known

  • Drug-level studies. A 2025 Cochrane review pooled trials of probiotics given to adults and children taking antibiotics. In the 40 trials that counted antibiotic-associated diarrhea (13,419 people), it affected 23% with probiotics and 27.4% without, low-certainty evidence. C. difficile diarrhea, a harder-to-treat gut infection, fell from 3.2% to 1.6%: about one case avoided for every 65 people. Many trials had links to probiotic companies. (Esmaeilinezhad 2025)
  • Timing. In a review of trials in people over 65, probiotics started within 2 days of the antibiotic lowered antibiotic-related diarrhea, while two large trials that began 48 hours after the first dose found no effect. No study we found tested how many hours to leave between a probiotic and an antibiotic dose. (Zhang 2022)
  • Who is at risk. In the Cochrane trials, side effects were no more common with probiotics (10.9% against 12.2%), and the authors judge short-term use likely safe for people on antibiotics whose immune systems work normally. NCCIH says the risk is greater with severe illness or a weak immune system, and possible harms include infections. (Esmaeilinezhad 2025, NCCIH)
  • Case reports. A review found 108 cases of Saccharomyces yeast in the blood, 73 in people given a Saccharomyces boulardii probiotic, often in intensive care or on tube or IV feeding. In intensive care patients, Lactobacillus found in the blood matched the probiotic capsule genetically. The FDA warns that premature babies given probiotics can get fatal infections, and reports a death from sepsis. (Vinayagamoorthy 2023, Yelin 2019, FDA)

What to do

  • Check with your prescriber or pharmacist first if you are in hospital, have a weak immune system, a central IV line or tube feeding, or a serious illness.
  • No source we read sets a number of hours between the two. In trials in older adults, starting the probiotic within 2 days of the antibiotic worked; starting later did not.
  • Call your doctor if diarrhea is severe or keeps going during or after the antibiotic, since C. difficile can be serious. Tell staff at once about a new fever while on probiotics in hospital.
  • Don't give probiotics to a premature baby unless the baby's care team advises it.
  • Don't stop or change a prescribed medicine on your own.

Sources

  1. Esmaeilinezhad Z, et al. Probiotics for the prevention of Clostridioides difficile-associated diarrhea in adults and children. Cochrane Database Syst Rev. 2025. PubMed 40931979 · doi:10.1002/14651858.CD006095.pub5
  2. Vinayagamoorthy K, et al. Epidemiology of Saccharomyces fungemia: A systematic review. Med Mycol. 2023. PubMed 36806741 · doi:10.1093/mmy/myad014
  3. Yelin I, et al. Genomic and epidemiological evidence of bacterial transmission from probiotic capsule to blood in ICU patients. Nat Med. 2019. PubMed 31700189 · doi:10.1038/s41591-019-0626-9
  4. National Center for Complementary and Integrative Health. Probiotics: Usefulness and Safety. Last updated August 2019. NCCIH
  5. Zhang L, et al. Early use of probiotics might prevent antibiotic-associated diarrhea in elderly (>65 years): a systematic review and meta-analysis. BMC Geriatr. 2022. PubMed 35794520 · doi:10.1186/s12877-022-03257-3
  6. US Food and Drug Administration. Risk of Invasive Disease in Preterm Infants Given Probiotics Formulated to Contain Live Bacteria or Yeast. Content current as of 29 September 2023. FDA