Colorectal Cancer Stage-Specific Fecal Bacterial Community Fingerprinting of the Taiwanese Population and Underpinning of Potential Taxonomic Biomarkers

Abstract

Despite advances in the characterization of colorectal cancer (CRC), it still faces a poor prognosis. There is growing evidence that gut microbiota and their metabolites potentially contribute to the development of CRC. Thus, microbial dysbiosis and their metabolites associated with CRC, based on stool samples, may be used to advantage to provide an excellent opportunity to find possible biomarkers for the screening, early detection, prevention, and treatment of CRC. Using 16S rRNA amplicon sequencing coupled with statistical analysis, this study analyzed the cause–effect shift of the microbial taxa and their metabolites that was associated with the fecal gut microbiota of 17 healthy controls, 21 polyps patients, and 21 cancer patients. The microbial taxonomic shift analysis revealed striking differences among the healthy control, polyps and cancer groups. At the phylum level, Synergistetes was reduced significantly in the polyps group compared to the healthy control and cancer group. Additionally, at the genus level and in association with the cancer group, a total of 12 genera were highly enriched in abundance. In contrast, only Oscillosprira was significantly higher in abundance in the healthy control group. Comparisons of the polyps and cancer groups showed a total of 18 significantly enriched genera. Among them, 78% of the genera associated with the cancer group were in higher abundance, whereas the remaining genera showed a higher abundance in the polyps group. Additionally, the comparison of healthy control and polyp groups showed six significantly abundant genera. More than 66% of these genera showed a reduced abundance in the polyps group than in healthy controls, whereas the remaining genera were highly abundant in the polyps group. Based on tumor presence and absence, the abundance of Olsenella and Lactobacillus at the genus level was significantly reduced in the patient group compared to healthy controls. The significant microbial function prediction revealed an increase in the abundance of metabolites in the polyps and cancer groups compared to healthy controls. A correlation analysis revealed a higher contribution of Dorea in the predicted functions. This study showed dysbiosis of gut microbiota at the taxonomic level and their metabolic functions among healthy subjects and in two stages of colorectal cancer, including adenoma and adenocarcinoma, which might serve as potential biomarkers for the early diagnosis and treatment of CRC.

Gut bacteria and sex differences in colorectal cancer

“…Dorea can adhere to cancer cells and may give this genus a competitive advantage in the cancerous CRC environment [36]. A study of 17 healthy controls, 21 polyps patients, and 21 cancer patients in Taiwan indicated that Dorea had significant superiority in CRC prediction [37], which is also reflected in our research.…”

The Firmicutes/Bacteroidetes Ratio as a Risk Factor of Breast Cancer

“…The F/B ratio is reflective of the balance of intestinal symbiotic microbiota. The F/B ratio has been studied in not only intestinal diseases such as IBD [ 8 ], but also in metabolic diseases such as obesity, NAFLD, inflammatory diseases, and cancers [ 12 , 22 ]. Intestinal microbiota can affect the entire body.…”

Cell-Free Supernatant of Odoribacter splanchnicus Isolated From Human Feces Exhibits Anti-colorectal Cancer Activity

“…have been considered to be bioindicators of human health; the risk of CRC or IBD is increased when their abundance levels are lower than those in healthy individuals ( Ferreira-Halder et al, 2017 ; Lawrence et al, 2020 ). Additionally, it was shown that the abundance of genus Odoribacter was decreased in the patients of CRC and polyps as compared with the control group ( Fang et al, 2021 ).…”