Short-chain fatty acids inhibit fluid and electrolyte loss induced by cholera toxin in proximal colon of rabbit in vivo

Short-chain fatty acids (SCFA), acetate, propionate, and butyrate, are prod uced by bacterial fermentation in the colon and stimulate Na+ and Cl- absor ption. We have studied the effects of SCFA on fluid and electrolyte absorpt ion during cholera toxin (CT) -induced colonic secretion in rabbit, using a steady-state perfusion technique with marker (PEG) dilution. Perfusion wit h SCFA significantly (P < 0.01) reduced colonic water secretion. Butyrate r educed water secretion the most (95%), followed by propionate (90%), and ac etate (80%). Butyrate significantly (P < 0.001) reduced secretions of Na+ ( 95.5%), K+ (75.2%), and Cl- (80.7%) ions but not HCO3- ions. Propionate sim ilarly reduced secretion of HCO3- (45.3%). Acetate significantly (P < 0.001 ) inhibited Na+ (76.4%) and Cl- (75.7%) secretion, but the inhibitions of K + (23.6%) and HCO3- (28.8%) were not significantly different from the contr ols. We conclude that SCFA reduce CT-induced water and electrolyte secretio n in the rabbit proximal colon, and its potential as an antidiarrheal agent should be further evaluated.