Randomised controlled trialindependent cross-checkabstract checked I-CHK-114 standard review
Chicken and beef affected gut bacteria similarly
Effect of the Consumption of Lean Red Meat from Beef (Pirenaica Breed) Versus Lean White Meat (Chicken) on the Gut Microbiota: A Randomized Cross-Over Study in Healthy Young Adults.
Overview
Rueda-De Torre I et al.. Mol Nutr Food Res 2025 · PMID 40711376 · DOI 10.1002/mnfr.70189
In 16 young adults, chicken and beef diets changed gut bacteria only modestly and similarly.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Do beef-based and chicken-based diets differ in their effect on the gut microbiota?
- How was the study done?
Randomised cross-over trial, two 8-week periods
- How many people, animals or samples were studied?
16
- What was actually found?
Both diets induced modest changes with no significant differences between groups. Alpha diversity declined significantly after the chicken diet, with an overall reduction across both interventions.
- How large was the observed effect?
Both diets induced modest changes with no significant differences between groups. Alpha diversity declined significantly after the chicken diet, with an overall reduction across both interventions.
- What do the results mean in everyday life?
No evidence that chicken specifically damages the gut flora.
- What are the study's limitations?
Very small sample; Short duration; No clinical outcomes
- What does it say about Elawady's specific claim?
Gives no support to a specific microbiome harm from chicken.
- Do the results apply to Germany and Europe?
EU population.
- What can explicitly not be concluded from this study?
Too small to exclude effects.
Scientific in-depth review
1. Full reference
- Authors
- Rueda-De Torre I et al.
- Journal
- Mol Nutr Food Res
- Year
- 2025
- Identifier
- PMID 40711376 DOI 10.1002/mnfr.70189
- Verification
- verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
Do beef-based and chicken-based diets differ in their effect on the gut microbiota?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised cross-over trial, two 8-week periods
- Population
Healthy young adults (mean age 20.1 y)
- Country
Spain
- Period
not stated
- Sample size
16
- Inclusion and exclusion criteria
as described in the abstract
4. Methods and endpoints
- Exposure / intervention
Conventional chicken 3 times per week for 8 weeks
- Comparator
Pirenaica beef 3 times per week
- Endpoints
16S rRNA microbiota composition, alpha diversity
- Statistical methods
as reported in the abstract
5. Actual results
- Results
Both diets induced modest changes with no significant differences between groups. Alpha diversity declined significantly after the chicken diet, with an overall reduction across both interventions.
- Absolute risks
not reported
- Authors' conclusion
Lean red meat and lean white meat produce similar effects on the gut microbiota.
6. Strengths
- Randomised cross-over
- Washout period
7. Weaknesses
- Very small sample
- Short duration
- No clinical outcomes
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Small trial; abstract only.
9. Assessment of the statistical interpretation
No between-diet difference; within-arm diversity drop is of unknown clinical meaning and was also seen overall.
10. Relevance to the specific claim
Only located RCT testing chicken intake and the human gut microbiome.
11. Independent contrary findings
12. Transferability to Germany and Europe
13. Overall methodological judgement
In 16 young adults, chicken and beef diets changed gut bacteria only modestly and similarly.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | not replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- Modern chicken breast is indigestible and damages the digestive system and gut microbiome. – Studies with mixed or unclear results