Dietary glutamine prevents the loss of intestinal barrier function and attenuates the increase in core body temperature induced by acute heat exposure

• Published in: British journal of nutrition Vol. 112; no. 10; pp. 1601 - 1610
• Main Authors: Soares, Anne D. N., Costa, Kátia A., Wanner, Samuel P., Santos, Rosana G. C., Fernandes, Simone O. A., Martins, Flaviano S., Nicoli, Jacques R., Coimbra, Cândido C., Cardoso, Valbert N.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.11.2014
• Subjects: Amino acids; Animals; Bacteria; Bacterial Translocation - drug effects; Biological and medical sciences; Body Temperature - drug effects; Diet; Dietary Supplements; Escherichia coli; Feeding. Feeding behavior; Fever - prevention & control; Fundamental and applied biological sciences. Psychology; Gastroenterology; Glutamine - pharmacology; Glutamine - therapeutic use; Heat; Heat Stroke - prevention & control; Hot Temperature; Intestinal Mucosa - drug effects; Intestinal Mucosa - microbiology; Intestinal Mucosa - pathology; Liver - microbiology; Mice; Nutritional Immunology; Permeability; Rodents; Stress; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Immunonutrients; Hyperthermia; Bacterial translocation; Intestinal permeability; Translocation; Nutrition; Digestive system; Barrier function; Acute; Body temperature; Gut; Environmental factor; Permeability; Infection; Cores; Heat; Aminoacid; Bacteriosis; Glutamine
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114514002608

Dietary glutamine (Gln) supplementation improves intestinal function in several stressful conditions. Therefore, in the present study, the effects of dietary Gln supplementation on the core body temperature (T core), bacterial translocation (BT) and intestinal permeability of mice subjected to acute heat stress were evaluated. Male Swiss mice (4 weeks old) were implanted with an abdominal temperature sensor and randomly assigned to one of the following groups fed isoenergetic and isoproteic diets for 7 d before the experimental trials: group fed the standard AIN-93G diet and exposed to a high ambient temperature (39°C) for 2 h (H-NS); group fed the AIN-93G diet supplemented with l-Gln and exposed to a high temperature (H-Gln); group fed the standard AIN-93G diet and not exposed to a high temperature (control, C-NS). Mice were orally administered diethylenetriaminepentaacetic acid radiolabelled with technetium (99mTc) for the assessment of intestinal permeability or 99mTc-Escherichia coli for the assessment of BT. Heat exposure increased T core (approximately 41°C during the experimental trial), intestinal permeability and BT to the blood and liver (3 h after the experimental trial) in mice from the H-NS group relative to those from the C-NS group. Dietary Gln supplementation attenuated hyperthermia and prevented the increases in intestinal permeability and BT induced by heat exposure. No correlations were observed between the improvements in gastrointestinal function and the attenuation of hyperthermia by Gln. Our findings indicate that dietary Gln supplementation preserved the integrity of the intestinal barrier and reduced the severity of hyperthermia during heat exposure. The findings also indicate that these Gln-mediated effects occurred through independent mechanisms.