Colitic Scid Mice Fed Lactobacillus spp. Show an Ameliorated Gut Histopathology and an Altered Cytokine Profile by Local T Cells

Scid mice transplanted with CD4+ T blast cells develop colitis. We investigated if the disease was influenced in colitic mice treated with antibiotic and fed Lactobacillus spp. Colitic scid mice were treated for 1 week with antibiotics (vancomycin/meropenem) followed or not followed by a 3-week administration of Lactobacillus reuteri DSM-12246 and Lactobacillus rhamnosus 19070-2 at 2 × 109 live bacteria/mouse/24 hours. After 12 weeks, the rectums were removed for histology, and CD4+ T cells from the mesenteric lymph nodes (MLN) were polyclonally activated for cytokine measurements. Irrespective of no treatment or treatments with antibiotics and probiotics, all mice transplanted with T cell blasts lost 10% of their body weight during the 12-week experimental period, whereas the nontransplanted mice had a 10% weight increase (P < 0.001). All mice treated with antibiotics but not fed probiotics showed severe gut inflammation, whereas only 2 of the 7 mice fed probiotics showed signs of severe colitis (P < 0.05). MLN-derived CD4+ T cells from this latter group of mice showed lower levels of interleukin-4 secretion (P < 0.05) and a tendency to higher interferon-γ production than mice not fed probiotics. Our data suggest that probiotics added to the drinking water may ameliorate local histopathological changes and influence local cytokine levels in colitic mice but not alter the colitis-associated weight loss.