Submitted:
08 August 2025
Posted:
11 August 2025
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Abstract
Keywords:
Introduction
Materials and Methods
16. S rRNA Sequence Data Analysis
Results
1. Association Between Clinical Variables and Microbiota Composition
- No significant differences in alpha diversity (Shannon index) were found between premenopausal and postmenopausal women (p=0.291).
- BMI categories (<30 vs. ≥30) did not significantly affect microbial richness or beta diversity (Bray–Curtis dissimilarity, PERMANOVA p=0.384).
- Recent history of antibiotic use, oral contraceptive use, menopausal status, or comorbidities showed no statistically significant association with microbial abundance at genus level (all p > 0.05).
2. Microbial Differences Between Tumor and Normal Breast Tissue
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Higher abundance in tumor tissue:
- ∘
- Ruminococcus, Eubacterium, Actinobacter, Stenotrophomonas, and Bacillus genera (all p < 0.05; Wilcoxon Signed-Rank Test).
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Higher abundance in normal tissue:
- ∘
- Lactobacillus, Staphylococcus, Bifidobacterium, Propionibacterium, Lactococcus, Proteobacteria, Burkholderia, Faecalibacterium, and Pelomonas (all p < 0.05).



3. Fecal Microbiota Analysis
Discussion
- Breast tissue has a distinct microbiome, differing between normal and cancerous areas.
- Certain genera may play tumor-promoting or tumor-suppressive roles.
- Microbial changes appear to be locally driven rather than linked to BMI or menopause.
- Your study adds to growing evidence that local dysbiosis could be a biomarker or target in breast cancer.
Conclusion
- Larger, multi-center studies involving ethnically and geographically diverse populations are needed to validate our findings and establish generalizability.
- Longitudinal studies could help determine whether microbiota alterations precede breast cancer development or are a consequence of tumor presence.
- Functional metagenomics and metabolomics approaches should be employed to better understand the metabolic and immune interactions between microbiota and breast tissue.
- The inclusion of healthy control groups and more detailed dietary assessments would improve the interpretability of stool microbiota data.
- Future studies should also explore whether microbiota modulation—via probiotics, prebiotics, dietary interventions, or targeted microbial therapies—may offer preventive or therapeutic benefits in breast cancer.
Declaration of İnterest Statement
Ethics Committee Approval
Funding Details
Data Availability Statement
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