The microbiome types of colorectal tissue are potentially associated with the prognosis of patients with colorectal cancer

Abstract

As the second leading cause of cancer worldwide, colorectal cancer (CRC) is associated with a poor prognosis. Although recent studies have explored prognostic markers in patients with CRC, whether tissue microbes carry prognostic information remains unknown. Here, by assessing the colorectal tissue microbes of 533 CRC patients, we found that Proteobacteria (43.5%), Firmicutes (25.3%), and Actinobacteria (23.0%) dominated the colorectal tissue microbiota, which was different from the gut microbiota. Moreover, two clear clusters were obtained by clustering based on the tissue microbes across all samples. By comparison, the relative abundances of Proteobacteria and Bacteroidetes in cluster 1 were significantly higher than those in cluster 2; while compared with cluster 1, Firmicutes and Actinobacteria were more abundant in cluster 2. In addition, the Firmicutes/Bacteroidetes ratios in cluster 1 were significantly lower than those in cluster 2. Further, compared with cluster 2, patients in cluster 1 had relatively poor survival (Log-rank test, p = 0.0067). By correlating tissue microbes with patient survival, we found that the relative abundance of dominant phyla, including Proteobacteria, Firmicutes, and Bacteroidetes, was significantly associated with survival in CRC patients. Besides, the co-occurrence network of tissue microbes at the phylum level of cluster 2 was more complicated than that of cluster 1. Lastly, we detected some pathogenic bacteria enriched in cluster 1 that promote the development of CRC, thus leading to poor survival. In contrast, cluster 2 showed significant increases in the abundance of some probiotics and genera that resist cancer development. Altogether, this study provides the first evidence that the tissue microbiome of CRC patients carries prognostic information and can help design approaches for clinically evaluating the survival of CRC patients.

Putrescine Supplementation Limits the Expansion of pks+ Escherichia coli and Tumor Development in the Colon

“…Harrold and colleagues ( 48 ) showed an increased abundance of the genera Bacillus and Lactobacillus in azure-winged magpies that received dietary supplementation with putrescine. Overall, we found that putrescine increased the Firmicutes / Bacteroidetes ratio, and a higher Firmicutes/Bacteroidetes ratio is linked to better survival in patients with colorectal cancer ( 51 ). In the phylum Firmicutes , we found an increase in the Limosilactobacillus genus in which Limosilactobacillus fermentum has been reported to produce peptidoglycan with anti-proliferative properties ( 52 ) and Limosilactobacillus reuteri has been shown to suppress colorectal tumorigenesis ( 53 ).…”

Identification of a Twelve-microRNA Signature with Prognostic Value in Stage II Microsatellite Stable Colon Cancer

“…Another emerging tool, circulating tumor DNA (ctDNA) analysis, has shown promise in identifying minimal residual disease [ 67 ], which results in a higher risk of recurrence for patients and may require closer surveillance or additional treatment options. Furthermore, the study of the gut microbiome is also a recent topic of interest for the assessment of both tumor onset and recurrent disease [ 68 , 69 ]. Lastly, exploring the tumor microenvironment [ 40 , 70 ], such as TILs, tumor-associated fribroblasts and stromal characteristics, and understanding the interactions between tumor cells and their microenvironment might provide valuable prognostic information.…”

Bones and guts – Why the microbiome matters

“…Despite reduced gut microbiota diversity, an abundance of Proteobacteria, Streptococcus, Campylobacter, and Moraxellaceae was found in both cancer bearing groups [36] . Interestingly, Proteobacteria, Streptococcus, and Campylobacter have all been linked to colorectal cancer [38] , [39] , [40] . In the non-cancer controls, Megamonas , Akkermansia, Clostridia, Gemmiger, and Paraprevotella were significantly more abundant [36] .…”