# Circulating gut microbial metabolites and risk of coronary heart disease: A prospective multi-stage metabolomics study

## TL;DR

This study identifies nine gut microbial metabolites linked to coronary heart disease risk across diverse populations, highlighting their potential as biomarkers or therapeutic targets.

## Contribution

The study systematically identifies and validates circulating microbial metabolites associated with coronary heart disease in racially diverse populations.

## Key findings

- Nine circulating microbial metabolites were consistently associated with incident coronary heart disease across diverse populations.
- Most associations were consistent across subgroups, though some effect modifications were observed by race, age, and obesity status.
- The findings suggest gut microbial metabolism plays a significant role in coronary heart disease development.

## Abstract

Despite growing evidence linking gut microbiota and microbial metabolites to human cardiometabolic health, few studies have systematically examined associations between circulating microbial metabolites and incident coronary heart disease (CHD).

We conducted a multi-stage metabolomics study involving five prospective cohorts. Discovery involved untargeted plasma metabolite profiling of 896 incident cases and 896 age-/sex-/race-matched controls (~300 pairs per race: Black, White, Asian) from the Southern Community Cohort Study (SCCS; baseline: 2002–2009) and the Shanghai Women’s Health Study and Shanghai Men’s Health Study (SWHS/SMHS; baseline: 1996–2000 and 2002–2006). In-silico validation was conducted in the Atherosclerosis Risk in Communities Study (ARIC; N = 3,539; 663 cases; baseline: 1987–1989) and Multi-Ethnic Study of Atherosclerosis (MESA; N = 3,860; 446 cases; baseline: 2000–2002). Lastly, a quantitative assay was developed and applied to a new set of 864 cases and 864 age-/sex-/race-matched controls (~260−340 pairs per race) from the SCCS and SWHS/SMHS. Conditional logistic regression estimated odds ratios (ORs) of incident CHD per standard deviation (SD) metabolite increase in discovery and quantitative stages with a nested case-control design. Cox regression was used in ARIC and MESA with a cohort design. Similar covariates were adjusted across stages, including age, sex (if applicable), race (if applicable), education, income, smoking status, alcohol consumption, physical activity, diet quality, and body mass index (BMI). The mean (SD) time between enrollment and CHD diagnosis was 5.6 (3.8), 6.9 (4.4), 15.0 (7.4), and 8.0 (4.9) years in the SCCS, SWHS/SMHS, ARIC, and MESA, respectively. The discovery stage identified 73 circulating microbiota-related metabolites associated with incident CHD (false discovery rate <0.10). Sixty-one metabolites were available for in-silico validation, of which 24 showed a significant association (p < 0.05) in the same direction as in the discovery. The targeted assay quantified eight of the 24 metabolites, with five significantly associated with incident CHD: imidazole propionate, 3-hydroxy-2-ethylpropionate, 4-hydroxyphenylacetate, trans-4-hydroxyproline, and 3-hydroxybutyrate; OR per SD ranged from 1.18 to 1.27 after adjustment for sociodemographics, lifestyles, and BMI. The targeted assay measured eight other promising microbial metabolites, four of which were significant: trimethylamine N-oxide, phenylacetyl-L-glutamine, 4-hydroxyhippuric acid, and indolepropionate. Most associations were consistent across participant subgroups by demographics, lifestyles, metabolic disease history, family CHD history, and follow-up time, although some potential effect modifications were found by race, age, obesity status, and follow-up time. The main limitations of the study are the observational design and the inability to validate all significant metabolites due to differences in metabolomic assay coverage across the three stages.

We identified and validated circulating gut microbial metabolites associated with incident CHD across diverse populations. Our findings offer novel epidemiological evidence on the importance of gut microbial metabolism in CHD development and highlight specific metabolites to prioritize for mechanistic investigation, biomarker validation, and therapeutic development.

Gut microbiota affects human cardiovascular health, including the risk of coronary heart disease.

Metabolomics technology has been used to examine the role of microbiota-related metabolites in the development of cardiovascular diseases.

Evidence from prospective studies with rigorous discovery and validation stages across racially and geographically diverse populations remains limited.

We conducted a multi-stage metabolomic study to evaluate blood levels of microbiota-related metabolites in association with risk of developing coronary heart disease among Black, White, and Asian adults.

We identified and validated nine circulating microbial metabolites linked to risk of coronary heart disease across diverse populations, including metabolites of amino acids, lipids, and xenobiotics.

Our findings underscore the importance of gut microbiota and microbial metabolism in cardiovascular disease development and highlight promising metabolites that may serve as novel biomarkers or therapeutic targets for future mechanistic and interventional studies.

The main limitation of this study is its observational design, which means we can identify metabolites associated with disease risk but cannot prove that metabolites caused the development of the disease.

Another limitation of this study is that we cannot confirm all potentially important metabolites due to differences in metabolomic assays across stages.

In this metabolomics study, Yulu Zheng and colleagues investigate associations between microbial metabolites and coronary heart disease, performing discovery and validation analyses using five different cohorts.