Colitic scid mice fed Lactobacillus spp. show an ameliorated gut histopathology and an altered cytokine profile by local T cells

Abstract

Background: 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. Methods: 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. Results: 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. Conclusions: 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. Copyright © 2005 by Lippincott Williams & Wilkins.