Characterization of human breast tissue microbiota from core needle biopsies through the analysis of multi hypervariable 16S-rRNA gene regions

Abstract

Breast microbiota compositions are not well understood, and a few recent reports have begun to explore the correlation between breast tissue dysbiosis and cancer. Given that various methods for breast microbiota detection were used, the aim of the present paper was to clarify which hypervariable region of the 16S-rRNA gene (V2, V3, V4, V6 + 7, V8, and V9) is the most informative for breast tissue microbiota. Core needle biopsies (CNBs) were compared with surgical excision biopsies (SEBs) to find a less invasive form of recovery useful for the analysis of a larger statistical population and potentially for diagnostic use of breast tissue microbiota. Finally, this study was the first to analyse the breast microbiota of tumours and paired normal tissues of a Mediterranean population. Our findings showed that the V3 region is the most informative for breast tissue microbiota, accounting for 45% of all reads. No significant differences were found between CNB and SEB specimens in terms of total reads and numbers of Operational Taxonomic Units (OTUs). Moreover, we find that more similarities than differences exist between tumours and adjacent normal tissues. Finally, the presence of the Ralstonia genus is associated with breast tissue.

Microbiome and Breast Cancer: New Role for an Ancient Population

“…Breast and milk microbiomes are almost similar. The most abundant phyla of both breast tissue and breast milk are Firmicutes, Actinobacteria, and Bacteroidetes (36). It is observed that frequent bacterial strains, including Staphylococcus, Serratia, Corynebacteria, and Streptococcus are the most abundant bacteria in milk (48).…”

The Important Role of Breast Microbiota in Breast Cancer

“…Smith et al [30] to NHW tumors, which may explain part of the BC racial disparities. Notably, Costantini et al [29] have found an increase of Ralstonia genus in cancerous samples relative to healthy-adjacent tissues from the same patient. Concomitantly, the authors have also reported decreased relative abundance of Methylobacterium in the cancerous samples, which is consistent with the findings of Wang et al [10].…”

“…Costantini et al [29] were the first to reveal that the genus Ralstonia, Proteobacteria phylum, is the most abundant genus in breast tissue since previously the genus had only been associated with human milk [85]. The findings of the increased relative abundance of Ralstonia in cancerous samples compared to healthy controls suggest possible pro-carcinogenic properties of the genus.…”

Indoxylsulfate, a Metabolite of the Microbiome, Has Cytostatic Effects in Breast Cancer via Activation of AHR and PXR Receptors and Induction of Oxidative Stress

“…Oncobiosis refers to the transformation of the microbiome in patients with neoplastic diseases. Several studies demonstrated oncobiosis in the distal gut [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], the breast microbiome [ 19 , 20 , 21 , 22 , 23 , 24 ], and oral and urinary microbiomes [ 22 ] in breast cancer patients. A majority of the reports show decreased diversity in breast cancer patients compared to controls [ 1 , 2 , 3 , 4 , 5 , 8 , 9 , 12 , 13 , 14 , 15 , 18 ].…”