Distinct microbes, metabolites, and the host genome define the multi-omics profiles in right-sided and left-sided colon cancer.

Background: Studies have reported clinical heterogeneity between right-sided colon cancer (RCC) and left-sided colon cancer (LCC). However, none of these studies used multi-omics analysis combining genetic regulation, microbiota, and metabolites to explain the site-specific difference.

Methods: Here, 494 participants from a 16S rRNA gene sequencing cohort (50 RCC, 114 LCC, and 100 healthy controls) and a multi-omics cohort (63 RCC, 79 LCC, and 88 healthy controls) were analyzed. 16S rRNA gene, metagenomic sequencing, and metabolomics analyses of fecal samples were evaluated to identify tumor location-related bacteria and metabolites. Whole-exome sequencing (WES) and transcriptome sequencing (RNA-seq) were conducted to obtain the mutation burden and genomic expression pattern.

Results: We found unique profiles of the intestinal microbiome, metabolome, and host genome between RCC and LCC. The bacteria Flavonifractor plautii (Fp) and Fusobacterium nucleatum, the metabolites L-phenylalanine, and the host genes PHLDA1 and WBP1 were the key omics features of RCC; whereas the bacteria Bacteroides sp. A1C1 (B.A1C1) and Parvimonas micra, the metabolites L-citrulline and D-ornithine, and the host genes TCF25 and HLA-DRB5 were considered the dominant omics features in LCC. Multi-omics correlation analysis indicated that RCC-enriched Fp was related to the accumulation of the metabolite L-phenylalanine and the suppressed WBP1 signal in RCC patients. In addition, LCC-enriched B.A1C1 was associated with the accumulation of the metabolites D-ornithine and L-citrulline as well as activation of the genes TCF25, HLA-DRB5, and AC079354.1.

Conclusion: Our findings identify previously unknown links between intestinal microbiota alterations, metabolites, and host genomics in RCC vs. LCC, suggesting that it may be possible to treat colorectal cancer (CRC) by targeting the gut microbiota-host interaction. Video Abstract.