The protective effect of VSL#3 on intestinal permeability in a rat model of alcoholic intestinal injury

Background: This study aimed to investigate the mechanism of the probiotic VSL#3 in acute alcoholic intestinal injury, and evaluate the effect of VSL#3, glutamine, VSL#3+glutamine and heat-killed VSL#3 therapy in a rat model. Methods: Six-to eight-week-old male wild-type rats were divided into seven groups. To establish the acute alcohol liver disease model, rats received three doses of corn starch dissolved in PBS/40% alcohol administered intra-gastrically every 12 hours. Treatment groups received an intra-gastric dose of VSL#3, Glutamine, heat-killed VSL#3, or VSL#3+Glutamine 30 minutes prior to alcohol administration. The placebo group was treated with PBS prior to alcohol administration. TNF alpha and endotoxin in plasma was measured by ELISA and Tachypleus Ameboctye Lysate assays, and electron microscopy, Western blotting, and reverse transcription polymerase chain reaction were used to identify the mechanisms of VSL#3 in the regulation of epithelial permeability. Results: First, compared with control group, endotoxin and TNF alpha in alcohol group was obviously high. At the same time, in VSL#3 group, the expression of endotoxin and TNF alpha obviously lower than the alcohol group. And the trends of the expression of tight junction proteins in these groups were reversed with the change of endotoxin and TNF alpha. Second, compared the groups of VSL#3 with glutamine, VSL#3+glutamine and heat-killed VSL#3, we found that both VSL#3 and heat-killed VSL#3, glutamine were as effective as VSL#3+glutamine in the treatment of acute alcohol liver disease, the expression of endotoxin and TNF alpha were lower than the alcohol group, and tight junction proteins were higher than the alcohol group whereas the expression of tight junction proteins were higher in VSL#3+glutamine group than either agent alone, but have no significant difference. Conclusion: We conclude that VSL#3 treatment can regulate the ecological balance of the gut microflora, preventing passage of endotoxin and other bacterial products from the gut lumen into the portal circulation and down-regulating the expression of TNF alpha, which could otherwise down-regulate the expression of tight junction proteins and increase epithelial permeability.