It is well-known that African Americans (AAs) face a higher risk and burden of colorectal cancer (CRC), but which genetic pathways or environmental/social determinants add to the risk of colorectal cancer are not well-known. Our overall working hypothesis is that the archaea in the human gut lumen are different in AAs compared to Non-Hispanic Whites (NHWs) and this difference (either in the numbers of archaea, types and/or function) contributes to the racial disparities observed in CRC. With this hypothesis, the study will use an existing sample set of AAs and NHWs with and without polyps. The first aim will determine M.Smithii and other archaea in AAs with and without polyps vs. NHWs with and without polyps using qPCR, amplicon and metagenomic sequencing. The second aim will examine genomic differences of M.smithii isolates from fecal samples of AAs with and without polyps vs NHWs with and without polyps. This will be the first study to examine archaea in the gut microbiome of AAs; and look at archaea diversity and functional potential in AAs with and without polyps and appropriate NHW controls, to understand CRC disparities in AAs. If differences are found similar to our preliminary data, manipulation of the archaea in AAs at risk for CRC can be considered, after further studies in larger cohorts.