Soheil Varasteh
1,2
, Saskia Braber
1
*
, Peyman Akbari
1,2
, Johan Garssen
2,3
, Johanna Fink-
Gremmels
1
1
Division of Veterinary Pharmacy, Pharmacology and Toxicology, Utrecht University, Utrecht, The
Netherlands,
2
Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science,
Utrecht University, Utrecht, The Netherlands,
3
Nutricia Research, Utrecht, The Netherlands
*
S.Braber@uu.nl
Abstract
High ambient temperatures negatively affect the human well-being as well as animal wel-
fare and production. The gastrointestinal tract is predominantly responsive to heat stress.
The currently available information about the multifaceted response to heat stress within dif-
ferent parts of the intestine is limited, especially in avian species. Hence, this study aims to
evaluate the heat stress-induced sequence of events in the intestines of chickens. Further-
more, the gut health-promoting effect of dietary galacto-oligosaccharides (GOS) was inves-
tigated in these heat stress-exposed chickens. Chickens were fed a control diet or diet
supplemented with 1% or 2.5% GOS (6 days) prior to and during a temperature challenge
for 5 days (38
–
39°C, 8h per day). The parameters measured in different parts of the intes-
tines included the genes (qPCR) HSF1, HSF3, HSP70, HSP90, E-cadherin, claudin-1, clau-
din-5, ZO-1, occludin, TLR-2, TLR-4, IL-6, IL-8, HO-1, HIF-1
α
) and their associated proteins
HSP70, HSP90 and pan-cadherin (western blots). In addition, IL-6 and IL-8 plasma concen-
trations were measured by ELISA. In the jejunum, HSF3, HSP70, HSP90, E-cadherin, clau-
din-5, ZO-1, TLR-4, IL-6 and IL-8 mRNA expression and HSP70 protein expression were
increased after heat stress exposure and a more pronounced increase in gene expression
was observed in ileum after heat stress exposure, and in addition HSF1, claudin-1 and HIF-
1
α
mRNA levels were upregulated. Furthermore, the IL-8 plasma levels were decreased in
chickens exposed to heat stress. Interestingly, the heat stress-related effects in the jejunum
were prevented in chickens fed a GOS diet, while dietary GOS did not alter these effects in
ileum. In conclusion, our results demonstrate the differences in susceptibility to heat stress
along the intestine, where the most obvious modification in gene expression is observed in
ileum, while dietary GOS only prevent the heat stress-related changes in jejunum.
Differences in Susceptibility to Heat Stress along the Chicken Intestine and the Protective Effects of Galacto-Oligosaccharides. Available from: https://www.researchgate.net/publication/282277141_Differences_in_Susceptibility_to_Heat_Stress_along_the_Chicken_Intestine_and_the_Protective_Effects_of_Galacto-Oligosaccharides [accessed Oct 22, 2015].
