Trimethylamine N-oxide (TMAO) in heat stroke: molecular mechanisms from gut dysbiosis to multi-organ injury
6 affiliations
- 1School of Pharmacy, Southern Medical University, Guangzhou, China
- 2Department of Pharmacy, People's Liberation Army General Hospital of Southern Theater Command, Guangzhou, China
- 3The First School of Clinical Medicine, Southern Medical University, Guangzhou, China
- 4The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
- 5Department of Emergency, People's Liberation Army General Hospital of Southern Theater Command, Guangzhou, China
- 6Department of General Medicine, People's Liberation Army General Hospital of Southern Theater Command, Guangzhou, China
Abstract
Heat stroke, a life-threatening condition characterized by core hyperthermia (≥40 °C), central nervous system dysfunction, and multi-organ failure with mortality rates of 20–70%, is increasingly recognized as a systemic inflammatory and hemodynamic disorder rather than a purely thermoregulatory collapse. Among the emerging mediators of its pathophysiology, trimethylamine N-oxide (TMAO)—a gut microbiota-derived metabolite generated from dietary choline, L-carnitine, and betaine—has attracted growing attention as a molecular link between heat-induced gut dysbiosis and multi-organ injury. This review synthesizes current evidence on the physiological and molecular mechanisms whereby TMAO is proposed to aggravate heat stroke pathology, including: (1) NLRP3 inflammasome activation via ROS-TXNIP, SIRT3-SOD2-mtROS, and cathepsin B-mediated pathways; (2) endothelial dysfunction through tight junction disruption, eNOS/NO suppression, and ALDH2/ROS/GSDMD-dependent pyroptosis; (3) platelet hyperreactivity and thrombosis through enhanced Ca2+ mobilization and IP3 signaling; (4) mitochondrial oxidative stress and bioenergetic failure; and (5) neuroinflammation via the gut–brain axis. We further discuss the concentration-dependent duality of TMAO as a chemical chaperone versus a pathological mediator, and evaluate translational strategies targeting TMAO metabolism, including gut microbiota modulation, TMA lyase inhibition, and NLRP3 blockade. Importantly, the majority of the mechanistic evidence synthesized herein derives from disease models other than heat stroke (e.g., atherosclerosis, chronic kidney disease, obesity, aging, preeclampsia, and ischemic stroke); direct evidence obtained in heat-stroke settings remains limited, and several proposed pathways should be regarded as hypotheses awaiting heat-stroke-specific validation. Elucidating TMAO-dependent mechanisms may therefore inform future biomarker development and therapeutic investigation—both of which require clinical validation in heat-stroke patients—in this increasingly prevalent climate-sensitive disease.
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BibTeX
@article{wu2026trimethylamine,
title = {{Trimethylamine N-oxide (TMAO) in heat stroke: molecular mechanisms from gut dysbiosis to multi-organ injury}},
author = {Qiong Wu and Qiong Wu and Guodong Lin and Guodong Lin and Guodong Lin and Yuanyuan Ou and Bo Ji and Zhiguo Pan and Zhiguo Pan and Zhiguo Pan and Yu Shao},
journal = {Frontiers in Physiology},
year = {2026},
month = oct,
doi = {10.3389/fphys.2026.1983362},
url = {https://doi.org/10.3389/fphys.2026.1983362},
note = {CC BY},
}
RIS
TY - JOUR
TI - Trimethylamine N-oxide (TMAO) in heat stroke: molecular mechanisms from gut dysbiosis to multi-organ injury
AU - Qiong Wu
AU - Qiong Wu
AU - Guodong Lin
AU - Guodong Lin
AU - Guodong Lin
AU - Yuanyuan Ou
AU - Bo Ji
AU - Zhiguo Pan
AU - Zhiguo Pan
AU - Zhiguo Pan
AU - Yu Shao
PY - 2026
DA - 2026/10/23
JO - Frontiers in Physiology
DO - 10.3389/fphys.2026.1983362
UR - https://doi.org/10.3389/fphys.2026.1983362
AB - Heat stroke, a life-threatening condition characterized by core hyperthermia (≥40 °C), central nervous system dysfunction, and multi-organ failure with mortality rates of 20–70%, is increasingly recognized as a systemic inflammatory and hemodynamic disorder rather than a purely thermoregulatory collapse. Among the emerging mediators of its pathophysiology, trimethylamine N-oxide (TMAO)—a gut microbiota-derived metabolite generated from dietary choline, L-carnitine, and betaine—has attracted growing attention as a molecular link between heat-induced gut dysbiosis and multi-organ injury. This review synthesizes current evidence on the physiological and molecular mechanisms whereby TMAO is proposed to aggravate heat stroke pathology, including: (1) NLRP3 inflammasome activation via ROS-TXNIP, SIRT3-SOD2-mtROS, and cathepsin B-mediated pathways; (2) endothelial dysfunction through tight junction disruption, eNOS/NO suppression, and ALDH2/ROS/GSDMD-dependent pyroptosis; (3) platelet hyperreactivity and thrombosis through enhanced Ca2+ mobilization and IP3 signaling; (4) mitochondrial oxidative stress and bioenergetic failure; and (5) neuroinflammation via the gut–brain axis. We further discuss the concentration-dependent duality of TMAO as a chemical chaperone versus a pathological mediator, and evaluate translational strategies targeting TMAO metabolism, including gut microbiota modulation, TMA lyase inhibition, and NLRP3 blockade. Importantly, the majority of the mechanistic evidence synthesized herein derives from disease models other than heat stroke (e.g., atherosclerosis, chronic kidney disease, obesity, aging, preeclampsia, and ischemic stroke); direct evidence obtained in heat-stroke settings remains limited, and several proposed pathways should be regarded as hypotheses awaiting heat-stroke-specific validation. Elucidating TMAO-dependent mechanisms may therefore inform future biomarker development and therapeutic investigation—both of which require clinical validation in heat-stroke patients—in this increasingly prevalent climate-sensitive disease.
SN - 1664-042X
ER -