Probiotics Reduce the Inflammatory Response Induced by a High-Fat Diet in the Liver of Young Rats

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in the pediatric population. Preliminary evidence suggests a potential therapeutic utility of probiotics for this condition. Here, we tested the potential effect of the probiotic VSL#3 (a multistrain preparation composed of Streptococcus thermophilus and several species of Lactobacillus and Bifidobacteria) on oxidative and inflammatory damage induced by a high-fat diet in the liver of young rats. At weaning, young male Sprague-Dawley rats were randomly divided into 3 groups (n = 6) fed a standard, nonpurified diet (Std; 5.5% of energy from fat) or a high-fat liquid diet (HFD; 71% of energy from fat). One of the HFD groups received by gavage VSL#3 (13 X 10(9) bacteria.kg(-1).d(-1)). After 4 wk, the HFD rats had greater body weight gain, fat mass, serum aminotransferase, and liver weight than rats fed the Std diet. The HFD induced liver lipid peroxidation, tumor necrosis factor (TNF alpha) production, protein S-nitrosylation, inducible nitric oxide synthase (NOS), cyclooxygenase (COX)-2 expression, and metalloproteinase (MMP) activity. Moreover, in the HFD group, PPAR alpha expression was less than in rats fed the Std diet. In rats fed the HFD diet and treated with VSL#3, liver TNF alpha levels, MMP-2 and MMP-9 activities, and expression of iNOS and COX-2 were significantly lower than in the HFD group. In VSL#3-treated rats, PPAR alpha expression was greater than in the HFD group. A modulation of the nuclear factor-kappa B pathway by VSL#3 was also demonstrated. Our data suggest that VSL#3 administration could limit oxidative and inflammatory liver damage in patients with NAFLD. J. Nutr. 139: 905-911. 2009.