Randomised controlled trialindependent cross-checkabstract checked I-ABX-128 standard review
About 1 in 4 women got thrush after antibiotics
Effect of lactobacillus in preventing post-antibiotic vulvovaginal candidiasis: a randomised controlled trial.
Overview
Pirotta M et al.. BMJ 2004 · PMID 15333452 · DOI 10.1136/bmj.38210.494977.DE
23% of women developed vaginal yeast infection after a short antibiotic course.
Does the study support the specific claim? Partly · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Test probiotics against thrush after antibiotics
- How was the study done?
Randomised trial
- How many people, animals or samples were studied?
235 women
- What was actually found?
23% got thrush; probiotics did not help
- How large was the observed effect?
23% (18-29%)
- What do the results mean in everyday life?
Thrush after antibiotics is common and treatable
- What are the study's limitations?
No antibiotic-free comparison group
- What does it say about Elawady's specific claim?
Supports overgrowth, not 'planting fungi'
- Do the results apply to Germany and Europe?
High
- What can explicitly not be concluded from this study?
Rates in men or gut overgrowth
Scientific in-depth review
1. Full reference
- Authors
- Pirotta M et al.
- Journal
- BMJ
- Year
- 2004
- Identifier
- PMID 15333452 DOI 10.1136/bmj.38210.494977.DE
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Not stated in abstract.
2. Research question
Can oral or vaginal lactobacillus prevent vulvovaginitis after antibiotics?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised, placebo-controlled, double-blind factorial trial
- Population
Non-pregnant women 18-50 needing a short oral antibiotic course for a non-gynaecological infection
- Country
Australia
- Period
Not stated in abstract
- Sample size
278 enrolled; 235 analysed
- Inclusion and exclusion criteria
General practices and pharmacies in Melbourne
4. Methods and endpoints
- Exposure / intervention
Oral and/or vaginal lactobacillus
- Comparator
Placebo
- Endpoints
Post-antibiotic vulvovaginitis with microbiological evidence of candidiasis
- Statistical methods
Odds ratios
5. Actual results
- Results
Overall 55/235 (23%, 95% CI 18%-29%) developed post-antibiotic vulvovaginitis; lactobacillus did not prevent it (oral OR 1.06, vaginal OR 1.38).
- Absolute risks
23% incidence after a short antibiotic course
- Authors' conclusion
Lactobacillus to prevent post-antibiotic vulvovaginitis is not supported.
6. Strengths
- Randomised, blinded
- Microbiological confirmation
7. Weaknesses
- Trial stopped early
- Women only
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Incidence data come from all arms (observational within RCT).
9. Assessment of the statistical interpretation
About 1 in 4 women developed symptomatic candidal vulvovaginitis after a short course.
10. Relevance to the specific claim
Quantifies the real part of the claim: Candida overgrowth after antibiotics is common in women.
11. Independent contrary findings
Shows a treatable side effect, not 'planting fungi'.
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Supports the overgrowth element; does not support the idea that antibiotics contain or plant fungi.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Rates without antibiotics (no untreated control).