Colon Cancer Mutations Associated With The Gut Microbiota

An extremely important study on colon cancer concludes: “We found statistically significant associations between loss-of-function mutations in tumor genes and shifts in the abundances of specific sets of bacterial taxa, suggestive of potential functional interaction.”  Further, the correlation between bacterial types and tumor mutations allowed for predictions about interactions between the mutations and the downstream signaling pathways affected by these mutations.  One can expect future work to more clearly delineate the molecular mechanisms of interaction between the microbiota and cancer mutations.  In the meantime, once again – for the thousandth time it seems – the importance of the gut microbiota is emphasized.  Abstract:

Variation in the gut microbiome has been linked to colorectal cancer (CRC), as well as to host genetic variation. However, we do not know whether, in addition to baseline host genetics, somatic mutational profiles in CRC tumors interact with the surrounding tumor microbiome, and if so, whether these changes can be used to understand microbe-host interactions with potential functional biological relevance. Here, we characterized the association between CRC microbial communities and tumor mutations using microbiome profiling and whole-exome sequencing in 44 pairs of tumors and matched normal tissues. We found statistically significant associations between loss-of-function mutations in tumor genes and shifts in the abundances of specific sets of bacterial taxa, suggestive of potential functional interaction. This correlation allows us to statistically predict interactions between loss-of-function tumor mutations in cancer-related genes and pathways, including MAPK and Wnt signaling, solely based on the composition of the microbiome. In conclusion, our study shows that CRC microbiomes are correlated with tumor mutational profiles, pointing towards possible mechanisms of molecular interaction.