Metagenomic analysis of fecal samples in colorectal cancer Egyptians patients post colectomy: A pilot study

Abstract

One of the most prevalent malignancies that significantly affects world health is colorectal cancer (CRC). While genetics are involved in a portion of CRC patients, most cases are sporadic. The microbiome composition could be a new source of tumor initiation and progression. This research was conducted to investigate the microbiota composition of CRC patients post colectomy at taxonomic and functional levels. Using a next-generation sequencing approach, using an Illumina Novaseq 6000, the fecal samples of 13 patients were analyzed and the obtained data was subjected to a bioinformatics analysis. The bacterial abundance and uniqueness varied in CRC patients alongside differences in bacterial counts between patients. Bacteroides fragilis, Bacteroides vulgatus, Escherichia coli, and Fusobacterium nucleatum were among the pro-cancerous microorganisms found. Concurrently, bacteria linked to CRC progression were detected that have been previously linked to metastasis and recurrence. At the same time, probiotic bacteria such as Bifidobacterium dentium, Bifidobacterium bifidum, and Akkermansia muciniphila increased in abundance after colectomies. Additionally, numerous pathways were deferentially enriched in CRC, which emerged from functional pathways based on bacterial shotgun data. CRC-specific microbiome signatures include an altered bacterial composition. Our research showed that microbial biomarkers could be more usefully employed to explore the link between gut microbiota and CRC using metagenomic techniques in the diagnosis, prognosis, and remission of CRC, thereby opening new avenues for CRC treatment.

Keywords

• crc
• gut microbiota
• metagenomic
• dysbiosis
• tumor biomarker