The Study
Diet–microbiome associations in 10,068 individuals from the Human Phenotype Project to guide personalized nutrition
This study found that what people eat is linked to the types of bacteria in their gut — like how eating yogurt is often connected to certain good bacteria. But it didn’t change people’s diets to see if that actually caused the bacteria to change, so we can’t say eating more yogurt definitely makes those bacteria grow.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists tracked what 10,000 people ate and what gut bacteria they had. They found that eating unprocessed foods, coffee, yogurt, or milk changes specific gut bacteria in predictable ways — and these changes stick around for years.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 552 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — changing your diet could shift your gut bacteria in ways that may improve heart and metabolic health, even if the bugs themselves aren't the main cause.
- 2Unprocessed foods linked to higher gut bug diversity (r=0.26).
- 3Coffee linked to Lawsonibacter (r=0.43), yogurt to Streptococcus (r=0.42), milk to Bifidobacterium (r=0.31–0.36).
- 482.5% of bacteria changes matched predictions over 4 years.
- 5Diet explained 152× more health variation than gut bugs alone.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nature Medicine
Year
2026
Authors
Tomer Segev, Daniel Barak, Liron Zahavi, A. Godneva, M. Rein, David L. Krongauz, D. Samocha-Bonet, H. Rossman, A. Weinberger, E. Segal
Related Content
Claims (5)
Changes in diet or supplements can cause measurable changes in the types and amounts of bacteria in the gut within a few days.
Computer models that simulate personalized diets can predict changes in gut bacteria that correspond with improvements in a combined measure of heart and metabolic health.
Over four years, the relationship between diet and gut microbial species remains consistent, with 82.5% of species changing in abundance as predicted by dietary patterns, showing that diet reliably shapes gut microbiome composition over time.
Dietary patterns explain more differences in heart and metabolic health markers than the gut microbiome, with diet accounting for 25 times more variation than microbial factors alone.
Diets with more unprocessed foods are linked to greater diversity and richness of gut bacteria in adults.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.