- The gut microbiome influences human disease including Type 2 diabetes, obesity and metabolic syndrome and interacts with the innate immune system. The human cathelicidin antimicrobial peptide (hCAMP), an important component of the innate immune system, and vitamin D and xanthohumol, a natural compound found in beer hops, regulate its expression. The overall hypothesis of current research in the Gombart lab is that consumption of these micronutrients regulates expression of hCAMP in the gut and that this changes the composition of the bacteria in the gut. These changes may lead to reduced obesity while consuming a high fat diet due to changes in the metabolites produced by the bacteria that affect the metabolism of the host. The working hypothesis for this project is that the composition of the microbiota is different between the wild type (WT) C57BL/6J , humanized CAMP/wild type mice (TgW), Camp knockout mice (KO) and humanized CAMP/Camp knockout mice (TgK). 16s rRNA sequencing data were aligned to the Greengenes 13.8 16s rRNA database using QIIME 1.9 from which a high quality phylogenetic tree was created using FastTree 2.1.7. The phylogenetic distance between groups was measured using the weighted and unweighted versions of the UniFrac metric and alpha diversity was measured through the phylogenetic diversity metric. Permutational ANOVA showed significant differences in the composition of the microbiota between the different CAMP genotypes. Additionally, KO mice showed significantly lower measures of phylogenetic diversity than other CAMP genotypes. Several bacterial species and genera that varied significantly between genotypes were identified. This work furthers current knowledge on the interactions of the innate immune system with the microbiome.