Co-administration of a probiotic strain Lactobacillus plantarum LS/07 CCM7766 with prebiotic inulin alleviates the intestinal inflammation in rats exposed to N,N-dimethylhydrazine

The aim of this study was to determine the anti-inflammatory effects of preventive administration of a probiotic strain Lactobacillus plantarum LS/07 CCM7766 alone or in combination with prebiotic inulin or with flax-seed oil in the gut of rats, which developed chronic inflammation following administration of the pro-carcinogen N,N-dimethylhydrazine (DMH). After 28 weeks administration of probiotic/prebiotic-containing diet, rats were killed and their colons were examined by immunohistological criteria, whereas cytokines were determined in the jejunal mucosa. Application of DMH triggered the production of pro-inflammatory cytokines IL-2, IL-6, IL-17, and TNF-α, expression of pro-inflammatory mediators NF-κB, COX-2 and iNOS and caused depletion of goblet cells. Supplementing the diet with L. plantarum and its combination with the prebiotic abolished DMH-induced inflammatory process in the jejunal mucosa by inhibiting the production of pro-inflammatory cytokines and by stimulation of anti-inflammatory IL-10 cytokine synthesis, whereas concentration of TGF-β1 was not influenced significantly. Diet prevented a decrease in goblet cell numbers but numbers of mast cells were lowered only moderately. However, combined treatment of rats with L. plantarum and flax-seed oil had no significant effect on the parameters examined, except for decreased expression of NF-κB, in comparison with the negative control. Results indicate that the preventive administration of probiotic L. plantarum LS/07 CCM7766 alone or in combination with prebiotic inulin to rats with DMH-induced chronic inflammation can reduce inflammatory process in the jejunal and colon mucosa, probably indirectly, and involves down-regulation of synthesis of pro-inflammatory cytokines and suppression of NF-κB activity in mucosal cells.