Related Experiment Video

Updated: Jul 17, 2026

Murine Model of Thoracic Aortic Dissection Induced by Oral β-Aminopropionitrile and Subcutaneous Angiotensin II Infusion
05:31

Murine Model of Thoracic Aortic Dissection Induced by Oral β-Aminopropionitrile and Subcutaneous Angiotensin II Infusion

Published on: May 16, 2025

Gut microbe-generated metabolite trimethylamine N-oxide and risk of abdominal aortic aneurysm: a cohort study

Xinmin S Li1,2, Meng Wang3, Zeneng Wang1,2

  • 1Department of Heart, Blood, and Kidney Research, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.

European Heart Journal
|July 15, 2026
PubMed
Abstract

Insights

Higher levels of trimethylamine N-oxide (TMAO) in older adults are linked to increased risk of abdominal aortic aneurysm (AAA) development and adverse outcomes. This suggests TMAO is a potential target for AAA prevention.

Area of Science:

  • Cardiovascular Science
  • Metabolomics
  • Gerontology

Background:

  • Abdominal aortic aneurysms (AAAs) pose a significant mortality risk in older adults.
  • Trimethylamine N-oxide (TMAO), a gut microbe metabolite, is implicated in AAA risk and progression.
  • The predictive value of TMAO for AAA development in healthy older adults is unclear.

Purpose of the Study:

  • To investigate the association between circulating TMAO levels and the incidence of AAA development.
  • To determine if TMAO predicts adverse AAA outcomes in community-dwelling older adults.

Main Methods:

  • Quantified plasma TMAO levels in 4442 adults aged ≥65 years using mass spectrometry.
  • Utilized ultrasound screening and prospective follow-up for AAA assessment.
  • Employed multivariable models to analyze TMAO associations with AAA development and adverse events, adjusting for confounders.

Main Results:

  • Elevated TMAO levels correlated with larger aortic diameter and higher AAA risk.
  • Over 12.2 years, higher TMAO independently predicted adverse AAA events (repair, rupture, death).
  • Hazard ratios indicated a significant increased risk with higher TMAO levels.

Conclusions:

  • Higher TMAO levels are independently associated with increased AAA risk and adverse events in older adults.
  • TMAO emerges as a novel risk factor for abdominal aortic aneurysms.
  • TMAO represents a potential therapeutic target for AAA prevention strategies.
Keywords:
AAA repairAbdominal aortic aneurysmsAneurysm ruptureGut microbiomeTMAO

Related Concept Videos

Microbiota Modulation by Antibiotics01:21

Microbiota Modulation by Antibiotics

Antibiotics have revolutionized modern medicine by saving countless lives from bacterial infections. However, their widespread use has inadvertently harmed the delicate balance of the human gut microbiota. The gut microbiota, a complex community of bacteria, archaea, viruses, and fungi, plays a vital role in regulating metabolism, immune responses, and maintaining intestinal health. Antibiotics, especially broad-spectrum types, disrupt this ecosystem by eradicating both harmful and beneficial...
Gut-Brain Axis01:22

Gut-Brain Axis

The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as...
Dysbiosis of the Gut Microbiota01:18

Dysbiosis of the Gut Microbiota

The human gut microbiome includes a diverse array of microbial species, including beneficial commensals and opportunistic pathogens, which interact to support host health. These microbes contribute to essential functions such as nutrient metabolism, immune system modulation, and maintenance of intestinal barrier integrity. However, disruptions to this equilibrium—referred to as dysbiosis—can have widespread physiological consequences.Dysbiosis is often characterized by reduced microbial...
Microbiota of the Urogenital Tract01:28

Microbiota of the Urogenital Tract

The human urogenital system, once thought to be sterile in healthy individuals, is now recognized as a complex microbial habitat. Advancements in molecular sequencing techniques have revealed that even in healthy adults, the kidneys and bladder harbor microbial populations similar to those found in the distal urethra, albeit in much lower abundance. These resident microorganisms, while generally innocuous, can become opportunistic pathogens under conditions that alter the urogenital...