Microbiome Resource Center

Microbiome Resource Center

February 17, 2020
2 min read

Rise in gut microbial metabolite may elevate CHD risk

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Lu Qi

Healthy women with long-term changes in plasma trimethylamine N-oxide, a choline metabolite produced from gut microbiota, had an increased risk for CHD, which may be modified by healthy dietary patterns, according to a prospective nested case-control study published in the Journal of the American College of Cardiology.

“Our study provides novel information to the knowledge on the relation between trimethylamine N-oxide (TMAO) and heart disease,” Lu Qi, MD, PhD, FAHA, HCA Regents Distinguished Chair and Professor and director of the Tulane University Obesity Research Center, told Healio. “First, we for the first time showed temporal changes in blood TMAO over 10 years may better predict the risk of cardiovascular disease. Second, and more important, we showed that habitual dietary intake patterns might change the cardiovascular risk related to TMAO.”

Nurses’ Health Study data

Yoriko Heianza, RD, PhD, researcher in the department of epidemiology at Tulane University School of Public Health and Tropical Medicine, and colleagues analyzed data from 760 women from the Nurses’ Health Study aged 30 to 55 years who were free from nonfatal MI or fatal CHD at the second blood collection.

These women had available information on plasma TMAO levels from blood collections in 1989-1990 and 2000-2002. Other information was assessed regarding weight, height, physical activity, smoking habit, medication use, history of physician-diagnosed diseases and other characteristics collected from questionnaires.

Women with incident cases of CHD from the second blood collection through 2016 (n = 380) were matched with controls (n = 380).

Increases in TMAO during a 10-year period were significantly linked to an increased risk for CHD regardless of the TMAO level at the first or second blood collection (RR in the top tertile = 1.58; 95% CI, 1.05-2.38; RR per 1-standard deviation increment = 1.33; 95% CI, 1.06-1.67). Compared with patients with consistently low TMAO levels, those with elevated levels at both time points had the highest risk for CHD (RR = 1.79; 95% CI, 1.08-2.96).

Researchers observed that the relationship between TMAO and CHD was attenuated by the adherence to healthy dietary habits (P for interaction = .008) or a plant-based diet (P for interaction = .04).

“Healthy, plant-based dietary pattern rich in vegetables and fruits, whole grain foods and lower in red meat and processed meat may attenuate the risk,” Qi said in an interview.

Qi added that these findings may help cardiologists identify patients who are at high risk for CHD.

“Measuring longitudinal changes in TMAO may help identify high-risk populations of heart diseases. In addition, clinicians may recommend healthy plant-based diets to their patients,” he said.


Responses to dietary interventions

Paul A. Heidenreich

In a related editorial, Paul A. Heidenreich, MD, MS, professor of medicine (cardiovascular) at Stanford University School of Medicine, and Petra Mamic, MD, cardiovascular medicine fellow at Stanford University, wrote: “Dietary patterns with CV benefits, such as the aforementioned Mediterranean diet, Dietary Approaches to Stop Hypertension diet and other similar largely plant-based diets, are known to induce shifts in the gut microbiome. These alterations are believed to mediate at least some of the beneficial cardiometabolic effects of these diets. However, on the individual level, gut microbiota changes and downstream physiological responses to dietary interventions are highly variable, which may be explained by the gut microbiota diversity” – by Darlene Dobkowski

For more information:

Lu Qi, MD, PhD, FAHA, can be reached at lqi1@tulane.edu.

Disclosures: The authors of the study and editorial report no relevant financial disclosures.