OBJECTIVES/GOALS: To investigate the relationship between abnormal bacterial colonization of the gastrointestinal (GI) tract and systemic abnormalities in innate immunity as it contributes to the pathogenesis of rosacea. METHODS/STUDY POPULATION: This is a prospective observational study of patients with erythematotelangiectatic or papulopustular rosacea. The study participants will undergo urea breath testing for Helicobacter pylori (Hp) and hydrogen-methane breath testing for small intestinal bacterial overgrowth (SIBO). Colonic microbiome analysis will be performed using 16S rRNA sequencing of fecal samples. Further, key pro-inflammatory cytokines will be quantified from serum samples. Markers for rosacea subjects and subgroups will be compared by standard analysis of variance methods where appropriate, and Tukey studentized range tests will be done for specific comparisons. Chi-square tests will be used to assess group differences in categorical data. At least 42 subjects will be studied to provide 80% power atα-0.05. RESULTS/ANTICIPATED RESULTS: We hypothesize that the results of this study will support an observed relationship between abnormal GI bacterial colonization and systemic innate immunity abnormalities in rosacea as determined by three primary endpoints: a significantly greater prevalence of Hp and SIBO in rosacea participants, presence of pro-inflammatory cytokines linked to rosacea pathogenesis including interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and Granulocyte-macrophage colony-stimulating factor (GM-CSF), and observation of distinct, metabolically active colonic bacterial communities specific to rosacea participants. DISCUSSION/SIGNIFICANCE: By identifying rosacea as a cutaneous manifestation of a more systemic inflammatory disease, the results of this study will have implications for the development of important pharmacological interventions targeting key inflammatory pathways in rosacea pathogenesis.