Probiotics and C. difficile (C. diff): Prevention, Treatment Limits and Guideline Views
What the AGA, ACG and IDSA guidelines and Cochrane reviews say about probiotics and C. diff, why treatment is antibiotic-led, and why severe diarrhea needs urgent care.
Content last updated . This page has not been medically reviewed.
Read this first
C. diff (Clostridioides difficile) infection needs medical care. The NHS (UK) advises urgent help if you have diarrhea while taking or after recently taking antibiotics, bloody diarrhea or bleeding from the bottom, or diarrhea for more than 7 days. [1] It says treatment is usually a different antibiotic, and that infections can lead to serious problems such as sepsis. [1] It also says not to take medicine that stops diarrhea (such as loperamide), because that can stop the infection clearing. [1] A probiotic is not a substitute for that treatment. Do not stop or change a prescribed medicine without asking your prescriber.What guidelines and reviews say
Strain and product details
A 2015 meta-analysis found four probiotics improved primary prevention: S. boulardii, L. casei DN114001, a mixture of L. acidophilus and B. bifidum, and a mixture of L. acidophilus, L. casei and L. rhamnosus. [7] The AGA noted the largest treatment trial (134 patients) of S. boulardii reported a possible benefit with low-quality evidence, while L. rhamnosus ATCC 53103 was linked with more recurrence versus placebo, with a very wide uncertainty range. [3] Results do not transfer between strains. [8]Recurrence and fecal microbiota therapy
When C. diff returns, the NHS says people may be offered a fecal microbiota transplant after two or more recurrences. [1] The AGA (2024) suggests select use of fecal microbiota-based therapies after standard antibiotics to prevent recurrence in immunocompetent adults, and suggests against them in severely immunocompromised adults. [10] This is a medical procedure or approved product, not a probiotic supplement. See Fecal microbiota-based therapies and Probiotics vs microbiota-based medicines.Frequently asked questions
Do probiotics treat C. diff?
Proper evidence not found for treatment. The AGA recommends use only in clinical trials. [3]
Can probiotics prevent C. diff?
Cochrane found a small absolute reduction with low certainty. Guidelines disagree. [6][4]
Can probiotics prevent C. diff from coming back?
A meta-analysis found no tested probiotic significantly improved secondary prevention. [7]
Should I stop my antibiotic or take a probiotic instead?
No. Treatment is antibiotic-led, and any change should come from your prescriber. [1]
Is a probiotic the same as a fecal transplant?
No. Fecal microbiota therapies are a separate medical treatment. [10]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: promising but limited, mixed, insufficient evidence, Proper evidence not found. Trial amounts are study amounts, not advice.
| Question | What the source found | Label |
|---|---|---|
| Probiotics as part of treatment | AGA 2020: use only in clinical trials (no recommendation, knowledge gap). [3] Certainty low across outcomes. [3] | Insufficient evidence |
| Preventing C. diff in people on antibiotics | AGA 2020 suggests S. boulardii or specific two-, three- or four-strain combinations (conditional, low-quality evidence). [3] | Promising but limited |
| Same question, ACG (US, 2021) | Reported as recommending against probiotics for prevention. [4][5] | Mixed |
| Same question, IDSA/SHEA (US) | No formal recommendation. [4] | Insufficient evidence |
| Cochrane 2025 (47 trials, 15,260 people) | Relative risk 0.50, absolute reduction 1.6%, low certainty; about 65 people would need probiotics to prevent one case. [6] | Promising but limited |
| Preventing recurrence | A 2015 meta-analysis: none of the tested probiotics significantly improved secondary prevention (four trials). [7] | Insufficient evidence |
We could not read the ACG and IDSA/SHEA guideline texts, so those rows rely on published reviews of them. Ask a clinician what current guidelines say.
Who is at risk
The NHS lists age over 65, recent antibiotics, long hospital or care-home stays, a weakened immune system, acid-reducing medicines and a past C. diff infection as risks. [1] Several of these groups overlap with the people NCCIH says face a greater risk of harm from probiotics: those with severe illness or compromised immune systems. [2]
Limits and uncertainty
- The 2025 Cochrane review found a probiotic-company affiliation or financial support in 28 of 47 studies. [6]
- Large trials in people at low baseline risk are still needed. [6]
- NCCIH says which probiotics would be most useful against C. diff diarrhea, for how long, and at what amounts is uncertain. [2]
- A large trial in hospital patients aged 65 and over found no benefit from one lactobacilli and bifidobacteria product, with C. diff in 0.8% versus 1.2%. [9]
Safety
Cochrane 2025 concluded probiotics are likely not linked to adverse effects in people on antibiotics who are not immunocompromised. [6] NCCIH says the risk of harm is greater with severe illness or compromised immune systems. [2] Ask a clinician or pharmacist before using any probiotic if you are immunocompromised, hospitalized, have a central line, are pregnant, or are choosing for a child. [11] Pregnancy, kidney and liver conditions were not addressed for this topic in the sources we read. See Probiotic safety, bloodstream infection risk and medication interactions.
References
- NHS, Clostridioides difficile (C. diff) infection. Read 2026-10-22.
- NCCIH, Probiotics: Usefulness and Safety. Read 2026-10-22.
- Su GL et al., AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders, Gastroenterology 2020. Read 2026-10-22.
- Is Three Company or a Crowd? Comparing and Contrasting U.S. and European Clostridioides difficile Infection Guidelines, Microorganisms 2022. Read 2026-10-22.
- Controversies in the Prevention and Treatment of Clostridioides difficile Infection in Adults: A Narrative Review, Microorganisms 2023. Read 2026-10-22.
- Esmaeilinezhad Z et al., Probiotics for the prevention of Clostridioides difficile-associated diarrhea in adults and children, Cochrane Database Syst Rev 2025. Read 2026-10-22.
- McFarland LV, Probiotics for the Primary and Secondary Prevention of C. difficile Infections: A Meta-analysis and Systematic Review, Antibiotics 2015. Read 2026-10-22.
- McFarland LV et al., Strain-Specificity and Disease-Specificity of Probiotic Efficacy: A Systematic Review and Meta-Analysis, Front Med 2018. Read 2026-10-22.
- Allen SJ et al., Lactobacilli and bifidobacteria in the prevention of antibiotic-associated diarrhoea and Clostridium difficile diarrhoea in older inpatients (PLACIDE), Lancet 2013. Read 2026-10-22.
- Peery AF et al., AGA Clinical Practice Guideline on Fecal Microbiota-Based Therapies for Select Gastrointestinal Diseases, Gastroenterology 2024. Read 2026-10-22.
- NHS, Probiotics. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.