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

Abstract

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 (398C) 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 ( 99m Tc) for the assessment of intestinal permeability or 99m Tc-Escherichia coli for the assessment of BT. Heat exposure increased T core (approximately 418C 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.

Reduced fasting periods increase intestinal permeability in chickens

“…The observations on glutamine supplementation in our study were contrary to previous studies in which prophylactic use of glutamine has been shown to maintain intestinal IP in rats and humans (Mondello et al., ; Soares et al., ; Wang, Niu, et al., ; Zuhl et al., ). Experimental models, animal species and the severity of these models to increase IP may explain the difference in results for glutamine supplementation in maintaining IP.…”

“…In the aforementioned studies, glutamine was administered post‐challenge, while glutamine as a preventative treatment has also been utilized as reviewed by (Andrade et al., ; Wang, Wu, et al., ). In brief, glutamine has been shown to maintain IP in mice when fed before a heat stress challenge (Soares et al., ). Similarly, feeding glutamine before an exercise and intestinal ischaemia challenge maintained IP in humans (Zuhl et al., ) and rats (Wang, Niu, et al., ).…”

Bacterial translocation in critical illness

“…Glutamine, a conditionally‐essential amino acid, is the preferred metabolic fuel for enterocytes, and a recent study showed the addition of dietary glutamine prevented increased intestinal permeability and BT in a rodent model of heat shock (Soares et al . ). Another study demonstrated that BT was reduced when a specific nutritional combination diet including high protein, L‐leucine, fish oil and specific oligliosaccharides was administered to mice receiving chemotherapy (Faber et al .…”

Bacterial Translocation from Intestine: Microbiological, Immunological and Pathophysiological Aspects

“…Так, в условиях нарушения барьерных свойств кишечни-ка под влиянием стрессового воздействия профилактиче-ское применение пробиотиков оказывало протективный эффект [9]. Способность повышать резистентность КБ к БТ выявлена у глютамина, вводимого перорально [10,11].…”