Total DNA from samples of human feces was extracted using the ZymoBIOMICS DNA Miniprep Kit, HMP fecal DNA extraction protocol, Supplier M and Supplier Q. The ZymoBIOMICS DNA Miniprep Kit yielded a higher total amount of DNA (upper). Additionally, the HMP, Supplier M and Supplier Q protocols over-represented easy-to-lyse microbes, e.g. Bacteroidetes and Proteobacteria, biasing the microbial profile.