Heat stress as a model to study the effect of a gut health concept (Presan-Fx) on the intestinal barrier function of weanling piglets

Abstract Text:

An acute heat stress model is used to study effects on the intestinal barrier function. During heat stress the animal redistributes the blood supply to the periphery, leading to increased gut permeability. To mitigate the impairment on barrier function, a mixture of Presan-Fx (synergistic blend of organic acids, medium chain fatty acids, butyrates and a phenolic compound) was used in this model with weanling piglets. The objective of this study was to evaluate the effect of a heat stress challenge on intestinal barrier function and the role a gut health concept in it.  

Twenty four piglets were distributed over 4 treatments in a 2 x 2 factorial design, with a control diet with or without Presan-Fx (2 kg/ton), under the condition with or without heat challenge. After a 6 day adaptation period, animals in the heat stress groups were given an acute heat stress of 40°C for 10 h followed by 28°C for 24 h. Animals were monitored for growth performance and the barrier function was evaluated by morphological assessment, tight junction proteins and cytokine production.  

Heat stress decreased  average daily gain (ADG), but the impact was reversed significantly in animals fed Presan-Fx (see table). For the animals fed Presan-Fx villus height was higher and the crypt depth was lower after heat stress compared to the control, suggesting that enterocytes had less damaged villi and higher cell production.

 Table:Average daily growth and histology data

	No stress		Heat stress
	Control	Presan-Fx	Control	Presan-Fx	P-value
ADG 0-6, g	411.0	455.5	456.6	416.7	0.98
ADG 6-8, g			90.0A	341.7B	0.05
ADG 6-11, g	550.0	503.3
Villus height, µm	ND	ND	327.3A	421.2B	0.07
Crypt Depth. µm	ND	ND	74.5A	119.3B	0.08

ND=not determined

Heat stress decreased the overall expression of the tight junction proteins Claudin-4, Claudin-7 and Occludin and had no effect on E-cadherin. The dietary treatments did not influence the expression of tight junction proteins. However, the expression of 5 inflammatory cytokines Il-1α, IL-8, IL-10, IL-17 and IL-23) was decreased by the Presan-Fx as measured by Q-PCR.

In conclusion, an acute heat stress impaired intestinal barrier function. Adding Presan-Fx supported the animals with a better resistance to a heat stress challenge. 

Keywords:

Heat stress, Gut health, Intestinal barrier function