Breast Cancer Survivors and Healthy Women: Could Gut Microbiota Make a Difference?—“BiotaCancerSurvivors”: A Case-Control Study

Abstract

In this first analysis, samples from 23 BC survivors (group 1) and 291 healthy female controls (group 2) were characterised through the V3 and V4 regions that encode the “16S rRNA” gene of each bacteria. The samples were sequenced by next-generation sequencing (NGS), and the taxonomy was identified by resorting to Kraken2 and improved with Bracken, using a curated database called ‘GutHealth_DB’. The α and β-diversity analyses were used to determine the richness and evenness of the gut microbiota. A non-parametric Mann-Whitney U test was applied to assess differential abundance between both groups. The Firmicutes/Bacteroidetes (F/B) ratio was calculated using a Kruskal-Wallis chi-squared test. The α-diversity was significantly higher in group 1 (p = 0.28 × 10−12 for the Chao index and p = 1.64 × 10−12 for the ACE index). The Shannon index, a marker of richness and evenness, was not statistically different between the two groups (p = 0.72). The microbiota composition was different between the two groups: a null hypothesis was rejected for PERMANOVA (p = 9.99 × 10−5) and Anosim (p = 0.04) and was not rejected for β-dispersion (p = 0.158), using Unifrac weighted distance. The relative abundance of 14 phyla, 29 classes, 25 orders, 64 families, 116 genera, and 74 species differed significantly between both groups. The F/B ratio was significantly lower in group 1 than in group 2, p < 0.001. Our study allowed us to observe significant taxonomic disparities in the two groups by testing the differences between BC survivors and healthy controls. Additional studies are needed to clarify the involved mechanisms and explore the relationship between microbiota and BC survivorship.

Altered mucosal bacteria and metabolomics in patients with Peutz–Jeghers syndrome

“…The abnormal intestinal development in PJS patients may be related to the effects of intestinal metabolic changes on the brain-intestinal axis and intestinal mucosal epithelium. Similar metabolic abnormalities have been found in patients with ulcerative colitis, colon cancer, and breast cancer [ 65 – 68 ]. The above studies suggest that there is a potential association between differences in metabolic pathways and PJS.…”

Gut microbiota and female health

“…The study conducted by Bobin-Dubigeon et al [ 41 ] demonstrated a reduction in gut microbiota diversity, a relative enrichment in Firmicutes , and a depletion in Bacteroidetes among patients with breast cancer as compared to those of healthy women. In another controlled study, patients with breast cancer exhibited a lower abundance of some microbial taxa, including Bacteroidetes phylum , Firmicutes phylum , Verrucomicrobia phylum , Clostridium genus , Shigella genus , Bifidobacterium genus , Akkermansia muciniphila , Clostridium perfringens , Escherichia coli , Bacteroides uniformis , Clostridium hathewayi , and Faecalibacterium prausnitzii [ 42 ].…”

Epigenetics, Microbiota, and Breast Cancer: A Systematic Review

“…It has been observed that the composition of the gut and mammary microbiota may differ between patients diagnosed with breast cancer and healthy subjects due to a disruption in the balance of this commensal community (Table 4). This imbalance would result in an altered or dysbiotic state in the microbiota that could be implicated in the etiology of cancer, influencing the disease's prevention, diagnosis, and prognosis [6,12,13,22]. ↑ abundance of Veillonellaceae and Dialister in patients scheduled for systematic adjuvant treatment.…”