The effect of bifidobacteria on inflammatory reaction and expression of heat shock protein 70 in newborn rats

Objective To investigate Bifidobacteria's protective role against E.coli Lipopolysaccharide(LPS)induced inflammatory response in newborn Sprague-Dewlye rats,and evaluate its protective mechanisms in anti-inflammation.Methods Fed with rat milk substitute(RMS),40 newborn SD rats(48 hours old)were evenly divided into 4 randomized groups.Two groups were fed with RMS in the presence of LPS and one was given additional Bifidobacteria.Another two groups without LPS served as controls,and additional Bifidobacteria was given to one of them.The weight of the newborn rats was measured daily.After 5 day all the subjects were executed.The ileocecal intestinal tissue were taken for histological analysis by HE staining.HSP70 level in intestine,liver and lung were measured by Western blotting.Results(1)Two groups fed with RMS in the presence of LPS had diarrhea,abdominal distention,poor weight gain,activity reduction.These features were attenuated in the group treated with LPS plus Bifidobacteria.By factorial ANOVA,LPS treatment had effect on the weight gain(P0.05),Bifidobacteria treatment had no statistically significant effect on the weight gain(P0.05).(2)The ileocecal intestine samples from two groups fed LPS showed a striking metaplasia in the villous epithelium,this feature was attenuated in the group treated with LPS plus Bifidobacteria.(3)By factorial ANOVA,LPS and Bifidobacteria had statistically significant effect on the expression of HSP70 in the intestine,liver and lung.And LPS and Bifidobacteria had interact on each other(P0.05),which show that Bifidobacteria treatment is able to increase LPS-induced expression of HSP70 in the intestine,liver and lung.Conclusion These results show that bifidobacteria is able to decrease the damage caused by LPS induced inflammatory response.After colonization in intestine,Bifidobacteria is able to increase the expression of HSP70,which would be underlying protective mechanisms of Bifidobacteria.