Inhaled diesel exhaust particles result in microbiome-related systemic inflammation and altered cardiovascular disease biomarkers in C57Bl/6 male mice.

Published: 3 September 2021| Version 1 | DOI: 10.17632/2r4jdxbrb2.1
Danielle Phillippi,


The gut microbiota plays a vital role in host homeostasis and is associated with inflammation and cardiovascular disease (CVD) risk. Exposure to particulate matter (PM) is a known mediator of inflammation and CVD and is reported to promote dysbiosis and decreased intestinal integrity. However, the role of inhaled traffic-generated PM on the gut microbiome and its corresponding systemic effects are not well-characterized. Thus, we investigated the hypothesis that exposure to inhaled diesel exhaust particles (DEP) alters the gut microbiome and promotes microbial-related inflammation and CVD biomarkers. 4-6-wk-old male C57Bl/6 mice on either a low-fat (LF) or high-fat (HF) diet were exposed via oropharyngeal aspiration to 35 μg DEP suspended in 35 μl saline or saline only (CON) 2x/week for 30 days. To determine whether probiotics could prevent diet or DEP exposure mediated alterations in the gut microbiome or systemic outcomes, a subset of animals on the HF diet was treated orally with 0.3 g/day of Winclove Ecologic Barrier probiotics throughout the study. Our results show that inhaled DEP exposure alters gut microbial profiles, including reducing Actinobacteria and expanding Verrucomicrobia and Proteobacteria. We observed increased circulating LPS, altered circulating cytokines, and CVD biomarkers in DEP-exposed and HF diet mice. Furthermore, probiotics attenuated the reduction of Actinobacteria and expansion of Proteobacteria and mitigated inflammatory and CVD responses in DEP exposed and/or HF diet mice. Key findings of this study are that inhaled DEP exposure altered gut microbial profiles that play a role in systemic inflammation and early CVD biomarkers that can be mitigated with probiotics.



Environmental Toxicology, Microbiome