Work

Impact of moderate environmental heat stress during running exercise on circulating markers of gastrointestinal integrity in endurance athletes

Year: 2025

Type: article

Abstract: In the present study, we aimed to determine the effect of moderate ambient heat stress on exercise-provoked patterns of "leaky gut" biomarkers and stress markers in well-trained athletes. Eleven triathletes performed a strenuous 1-h treadmill run, both under normal ambient conditions (N, 18-21°C) as well as under moderate heat environmental conditions (H, 28-30°C). Core body temperature (Tc), heart rate (HR), and rating of perceived exertion (RPE) significantly increased under both conditions, with significantly higher values during and after the H run. We observed a significant main effect of acute exercise on circulating leukocyte numbers, release of cell-free human DNA (cfDNA) but not bacterial DNA (bacDNA), and on plasma levels of intestinal fatty-acid binding protein (I-FABP), lipopolysaccharide-binding protein (LBP), endotoxin (LPS), and D-lactate. Exercising under H conditions accelerated the mobilization of circulating neutrophils and lymphocytes, and significantly affected the release of cfDNA, D-lactate, I-FABP, creatinine, and blood potassium levels. Multiple correlation analysis revealed a significant association between Tc, max and exercise-provoked release of cfDNA (r = 0.583, p = 0.012) as well as with I-FABP (r = 0.554, p = 0.026). Our data indicate that acute exercising and heat stress may not only affect paracellular but also transcellular intestinal permeability.

Source: Physiological Reports

DOI: 10.14814/phy2.70305

Authors: Thomas Beiter, Gunnar Erz, Anna Würden, Andreas M. Nieß

Institutions: Universitätsklinikum Tübingen, University of Tübingen

Language: English

Topic: Thermoregulation and physiological responses

Subfield: Physiology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,050