Remodeling gut microbiota by Streptococcus thermophilus 19 attenuates inflammation in septic mice

Abstract

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is the leading cause of death in burn patients. Streptococcus thermophilus 19 is a highly effective probiotic, with well-studied health benefits, but its role in protecting viscera against injury caused by sepsis and the underlying mechanism is poorly understood. The goal of this study was to evaluate protection potency of S. thermophilus against inflammation in mice and evaluate the influence of sepsis and S. thermophilus on microbial community. We tested the utility of S. thermophilus 19 in attenuating inflammation in vitro and vivo of LPS-induced sepsis mouse model. We also evaluated the influence of sepsis and S. thermophilus on microbial community. In vitro, S. thermophilus 19 decrease the expression of inflammatory factors. Additionally, in a lipopolysaccharide-induced septic mouse model, mice administered the probiotic 19 was highly resistant to Lps and exhibited decreased expression of inflammatory factors compared to Lps-treated control mice. A MiSeq-based sequence analysis revealed that gut microbiota alterations in mice intraperitoneally injected with 1 mg/ml LPS were mitigated by the administration of oral probiotics 19. Together these findings indicate that S. thermophilus 19 may be a new avenue for interventions against inflammation caused by sepsis and other systemic inflammatory diseases. In an analysis of the gut microbiota of the all group mice, we found that sepsis is associated with gut microbiota and probiotics attenuate the inflammation through remodeling gut microbiota. ImportanceSepsis is life-threatening organ dysfunction which is the leading cause of death in burn patients. Although our understanding of sepsis has increased substantially in recent years, its still reported to be the leading cause of death in seriously ill patients. Evidences showed that gut microbiota play an important role in sepsis. Moreover, probiotics have been used to prevent numbers of gut health disorders and alleviate inflammation associated with some human diseases by promoting changes in the gut microbiota composition. Hence, to investigate the mechanism of probiotics in the treatment of sepsis has emerged. The significance of our research is in identifying the role of gut microbiota in sepsis and found an effective probiotic that reduces inflammation, S. thermophilus 19, and investigating the therapeutic effect and mechanism of S. thermophilus 19 on sepsis, which might be a new avenue for interventions against inflammation caused by sepsis and other systemic inflammatory diseases.