Cholera toxin-induced secretion in rats is reduced by a soluble fiber, gum arabic

Gum arabic (GA), a soluble fiber with emulsifying properties, enhances intestinal water and electrolyte absorption in normal and secreting rats. Our aim was to assess the effect of GA, 2.5 and 5.0 g/liter, on cholera toxin-induced water and electrolyte secretion in rat jejunum in vivo. After a 2-hr exposure to cholera toxin, jejunal segments of adult rats were perfused in vivo with at plasma electrolyte solution containing GA, 0, 2.5 or 5.0 g/liter. 24Na was used as a marker of sodium influx. Cholera toxin-induced secretion was reduced by GA, 2.5 and 5.0 g/liter. 24Na secretion into the lumen was reduced by GA. GA caused a morphological expansion of intercellular spaces in the villi but not crypts. In conclusion, GA promotes lumen to blood intestinal transport of water and sodium despite cholera toxin activation. These observations support a potential role for GA in enhancing the efficacy of ORS.