Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum (BL) attenuate cytokine expression in the lungs of weanling mice with peritonitis‐induced sepsis

Abstract

Overexpression of inflammatory cytokines in sepsis leads to organ dysfunction, including severe respiratory disorders. We previously showed that probiotics ameliorate sepsis‐induced intestinal injury. In this study, we evaluated the effects of LGG (109 CFU/ml, o.g.) and BL (109 CFU/ml, o.g.) on cytokine expression in lungs of mice subjected to cecal ligation and puncture (CLP) or sham laparotomy. Mice treated with LGG or BL had significantly improved 7‐day survival compared to untreated septic mice (43% and 50% vs 8% survival, respectively; p<0.01). At 24 hr post‐CLP, gene expression of TNFα, IL‐6, IL‐1β and IL‐10 were dramatically increased in lungs of septic mice compared to shams (p<0.05). In contrast, septic mice treated with LGG/BL had decreased lung cytokine mRNA levels (p<0.05). TNFα was also measured in lung homogenates and serum by ELISA. LGG/BL treatment decreased TNFα levels in lung homogenates of septic mice vs untreated septic mice (1.73±0.14 and 2.89±0.83 vs 9.27±2.66 pg/ml; p<0.05). However, there was no difference in serum TNFα levels between septic groups (59.89±15.68 and 39.99±4.55 vs 54.52±13.21 pg/ml; p=ns). In conclusion, probiotics confer a survival advantage in septic peritonitis which is associated with attenuated local cytokine expression in the lungs. Thus, LGG/BL may be novel therapeutic agents for the treatment of sepsis.