Heat-killed probiotic Lactobacillus plantarum affects the function of neutrophils but does not improve survival in murine burn injury

Probiotics have become of interest as therapeutics in trauma or sepsis-induced inflammation due to their ability to affects the immune response. However, their use is still under debate due to the potential risk of septicemia. Therefore, heat-killed probiotics offer a potential alternative, with recent research suggesting a comparable immunomodulating potential and increased safety. In a previous study, we demonstrated decreased mortality by administration of live Lactobacillus plantarum in a mouse burn-sepsis model. Neutrophils are an essential innate defense against pathogens. Therefore, our present study aims to understand the impact of heat-killed probiotic L. plantarum (HKLP) on neutrophil function. Utilizing an in vitro stimulation with HKLP and a burn-infection in vivo model, we determined that administration of HKLP induced significant release of granulocyte-colony stimulating factor (G-CSF) and stimulated the release of pro-and anti-inflammatory cytokines. HKLP had no impact on neutrophil function, such as phagocytosis, oxidative burst, and NETosis, but increased apoptosis and activated neutrophils. HKLP did not improve survival. Together, contrary to our hypothesis, heat-killed probiotics did not improve neutrophil function and survival outcome in a murine severe burn injury model.     

Distant microcirculatory changes after a major burn: effects of methyl prednisolone,dextran 40, heparin and normal saline

The effects of a 32 per cent BSA full-thickness dorsal scald burn on the mesenteric microcirculation was studied by in vivo microscopy in Sprague-Dawley rats. Arteriolar constriction by 25 per cent, venular dilation by 50 per cent, WBC sticking, red cell aggregation and platelet thromboembolism were seen. Blood samples revealed thrombocytopenia post burn. Post-burn intravenous treatment with methyl prednisolone, Dextran 40, heparin or normal saline did not change the vascular diameters. Methyl prednisolone reduced WBC sticking, and increased WBC and platelet counts in sampled blood. Dextran 40, heparin and normal saline had no effect on these parameters.