Gut microbiota have been associated with many different disorders, including cardiovascular disease. One common mechanism involves the production, from dietary components, of metabolites that enter the circulation and affect physiologic functions such as inflammation. We propose to perform a comprehensive screen of gut microbiota-derived metabolites that contribute to cardio-metabolic disorders. Using a panel of genetically diverse inbred strains of mice, we will identify microbes and microbiota-derived metabolites that associate with atherosclerosis, followed by validation in human cohorts and mechanistic studies in germ-free mice. The work will be done in three laboratories with complimentary skills: A. Lusis (genetics), F. Rey (microbiology), and Z. Wang (metabolomics). All of the investigators have worked together for several years. The proposal represents an extension of a screen we previously performed using a panel of 100 inbred strains of mice for atherosclerosis (900 mice total). In that screen, we observed over a 200-fold range of lesion development. We now propose to analyze the microbiomes (Aim 1) and plasma metabolomes (Aim 2) of the mice and to relate these to atherosclerosis traits. We will then prioritize the significant associations by studying these in an atherosclerosis case-control human population (Aim 3). Finally, we will study the mechanisms by which the metabolites affect disease using germ-free mouse models (Aim 4). In preliminary studies, the levels of trimethylamine-N-oxide, another microbe-derived molecule shown to contribute to human atherosclerosis, were significantly correlated with lesion development. And, using a subset of the panel, we identified two microbes (A. muciniphila and R. intestinalis) associated with cardiometabolic traits and showed that these exhibited the predicted effects when used to colonize mice. These preliminary studies provide strong validation for the overall approach. We anticipate identifying several novel metabolites associated with atherosclerosis and related traits, and exploring the underlying mechanisms. This should pave the way for novel therapies that target the microbiome.

Public Health Relevance

We propose a genetic screen to identify novel gut-microbiota-derived metabolites that contribute to cardio-metabolic disorders, such as atherosclerosis. An understanding of such metabolites and the microbes that produce them could lead to the development of novel therapies targeting gut microbes or downstream pathways.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL144651-01
Application #
9639635
Study Section
Atherosclerosis and Inflammation of the Cardiovascular System Study Section (AICS)
Program Officer
Olive, Michelle
Project Start
2019-01-15
Project End
2022-10-31
Budget Start
2019-01-15
Budget End
2019-10-31
Support Year
1
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095