Uncovering Microbial Composition in Human Breast Cancer Primary Tumour Tissue Using Transcriptomic RNA-seqOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers examined the microbial composition of primary breast tumor tissue versus normal breast tissue. They compared results across multiple breast cancer phenotypes in two independent cohorts.
How was it studied?
The team sequenced the transcriptome (rRNA depleted RNA-seq) of tumor and normal breast tissue from 23 individuals in Slovakia. They also analyzed 91 samples from a Chinese cohort in the SRA database, submitted by Sichuan University, using both Kraken2 and Metaphlan3 bioinformatics tools, finding Kraken2 more reliable for their data.
What did they find?
Proteobacteria were the most enriched group in breast tissue, followed by Firmicutes and Actinobacteria in both datasets. Slovak samples also showed notable Bacteroides, while Chinese samples had more frequent Cyanobacteria. The microbiome differed between cancerous and healthy tissue and across disease phenotypes defined by circulating tumor cells and other markers.
Why it matters
The findings reinforce that breast tissue is not sterile and harbors a distinct microbial signature. Differences linked to circulating tumor cells and other markers suggest the breast microbiome may track with tumor biology, though a causal role remains unestablished.