A metagenomic assessment of gut microbiota in Indian colon cancer patients

Abstract

Background: Gut microbiota plays an important role in the development of different diseases including colorectal cancer. The geography, lifestyle, and dietary habits of Indians are different from Western world, thus microbiome studies of Western population could not be extrapolated to their Indian counterparts. Method: Therefore, we have conducted a study on gut microbiota in Indian healthy subjects and patients of colon cancer using 16S ribosomal RNA Amplicon sequencing. Operational taxonomic units were calculated for different bacterial taxon including phylum, class, order, family, and genus level. Results: Observed results indicated a considerable difference in the bacterial diversity in both the groups. Phylum Firmicutes was significantly dominated in both the groups followed by Bacteroidetes, Actinobacteria, and Proteobacteria which clearly indicates the dominance of phylum Firmicutes in Indian population. Phylum Firmicutes and Actinobacteria were significantly abundant in the healthy group while phylum Bacteroidetes in the colon cancer group. Bacterial genera Megamonas, Megasphaera, Mitsuokella, and Streptococcus were significantly abundant in the healthy group and Veillonella, Prevotella, and Eubacterium in the colon cancer group. Bacterial genus Bradyrhizobium was present in the healthy group and Alistipes, Coprococcus, Dorea, and Rhodococcus were present in the colon cancer group but absent in the healthy group. Conclusion: There was a considerable difference in bacterial diversity in both the study groups indicating dysbiosis in the colon cancer group.