Air pollution exposure is known to contribute to the progression of cardiovascular disease (CVD) and there is increasing evidence that dysbiosis of the gut microbiome may also play a role in the pathogenesis of CVD, including atherosclerosis. To date, the effects of inhaled air pollution mixtures on the intestinal epithelial barrier (IEB), and microbiota profiles are not well characterized, especially in susceptible individuals with comorbidity. Thus, we investigated the effects of inhaled ubiquitous air-pollutants, wood-smoke (WS) and mixed diesel and gasoline *