Effect of probiotics preconditioning on intestinal mucosal barrier function after cardiopulmonary bypass in rats

Abstract

Objective To investigate the effect of probiotics preconditioning on intestinal mucosal barrier function in a rat model of cardiopulmonary bypass (CPB) . Methods Twenty-four adult male SD rats weighing 350-450 g were randomly divided into 3 groups ( n = 8 each) : group Ⅰ sham operation ( group S); group Ⅱ CPB and group Ⅲ probiotics + CPB. CPB was established between left carotid artery and right jugular vein and maintained for 60 min. Croup Ⅲ received intragastric instillation of probiotics 2 ml once a day for 7 consecutive days before CPB. Blood samples were collected at 2 h after CPB was terminated for determination of plasma D-lactate, TNF-and IL-6 concentrations and diamine oxidase (DAO) activity. Venous blood was obtained from portal vein for determination of LPS concentration and cultured. Liver, pancreas, spleen, kidney and mesenteric lymphnode (MLN) specimens were obtained under sterile condition and cultured for bacterial growth. The mucous membrane of small intestine was examined with electron microscope. Results CPB significantly increased plasma DAO activity, and D-lactate, IPS, TNF-α and IL-6 concentrations and the rate of bacteria-positive culture of portal venous blood, liver, MLN, lung and kidney in group Ⅱ as compared with group S. Probiotics preconditioning significantly attenuated the above-mentioned CPB-induced changes. Microscopic examination showed that probiotics preconditioning significantly ameliorated CPB-induced damage to the epithelium of the small intestine. Conclusion Probiotics preconditioning can significantly attenuate CPB-induced inflammatory response and protect the intestinal mucosal barrier function. Key words: Probiotics; Ischemic preconditioning; Cardiopuhnonary bypass; Intestinal mucosa