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The impact of exertional-heat stress on gastrointestinal integrity, gastrointestinal symptoms, systemic endotoxin and cytokine profile
journal contribution
posted on 2018-02-01, 00:00 authored by Rhiannon SnipeRhiannon Snipe, A Khoo, C M Kitic, P R Gibson, R J S CostaPURPOSE: The study aimed to determine the effects of exertional-heat stress on gastrointestinal integrity, symptoms, systemic endotoxin and inflammatory responses; and assess the relationship between changes in body temperature and gastrointestinal perturbations. METHODS: Ten endurance runners completed 2 h running at 60% [Formula: see text]O2max in hot (HOT: 35 °C) and temperate (TEMP: 22 °C)-ambient conditions. Rectal temperature (T re) and gastrointestinal symptoms were recorded every 10 min during exercise. Blood samples were collected pre- and post-exercise, and during recovery to determine plasma intestinal fatty acid binding protein (I-FABP), cortisol, bacterial endotoxin and cytokine profile. Calprotectin was determined from pre- and post-exercise faecal samples. Urinary lactulose:L-rhamnose ratio was used to measure intestinal permeability. RESULTS: Compared with TEMP, HOT significantly increased T re (1.4 ± 0.5 vs 2.4 ± 0.8 °C, p < 0.001), cortisol (26 vs 82%, p < 0.001), I-FABP (127 vs 432%, p < 0.001), incidence (70 vs 90%) and severity (58 counts vs 720 counts, p = 0.008) of total gastrointestinal symptoms. Faecal calprotectin and circulating endotoxin increased post-exercise in both trials (mean increase 1.5 ± 2.5 µg/g, p = 0.032, and 6.9 ± 10.3 pg/ml, p = 0.047, respectively), while anti-endotoxin antibodies increased 28% post-exercise in TEMP and decreased 21% in HOT (p = 0.027). However, intestinal permeability did not differ between trials (p = 0.185). Inflammatory cytokines were greater on HOT compared to TEMP (p < 0.05). Increases in T re were positively associated with I-FABP, IL-10, cortisol, nausea and urge to regurgitate (p < 0.05). CONCLUSIONS: Exertional-heat stress induces a thermoregulatory strain that subsequently injures the intestinal epithelium, reduces endotoxin clearance capacity, promotes greater cytokinaemia, and development of gastrointestinal symptoms.
History
Journal
European journal of applied physiologyVolume
118Issue
2Pagination
389 - 400Publisher
SpringerLocation
Berlin, GermanyPublisher DOI
ISSN
1439-6319eISSN
1439-6327Language
engPublication classification
C1.1 Refereed article in a scholarly journal; C Journal articleCopyright notice
2017, Springer-Verlag GmbH Germany, part of Springer NatureUsage metrics
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No categories selectedKeywords
CalprotectinEuhydrationI-FABPInflammationPermeabilityRunningScience & TechnologyLife Sciences & BiomedicinePhysiologySport SciencesINFLAMMATORY-BOWEL-DISEASEPHYSICAL-EXERCISEBLOOD-FLOWINTESTINAL PERMEABILITYCIRCULATORY ENDOTOXIN161-KM ULTRAMARATHONFECAL CALPROTECTINMEMBRANE VESICLESINTENSE EXERCISEULTRA-MARATHON
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