[Accepted version, unedited] Antibiotic resistant bacteria originating from the gut may modulate the mucosal immune response during sepsis and septic shock

The enrichment and diversity of gut microbiota play an important role in sepsis, but the role of gut microbiota composition and diversity in sepsis and septic shock has not yet been characterized. The impact of gut microbiota diversity on host immunological disorders and future treatments of inflammatory diseases are not yet characterized. Further, the association between the microbiota and immune development in sepsis remains unknown, and the underlying mechanisms are not well understood. The altered composition of gut microbiota during sepsis is profoundly associated with a loss of commensal bacteria and an overgrowth of potentially pathogenic bacteria; especially antibiotics resistance bacteria. The altered composition and diversity of gut microbiota especially AMR bacteria due to treatment with antibiotics may lead to the translocation of enteric bacteria across the epithelium and causes the pathogenesis of sepsis. Disruptions of gut microbiota diversity are directly associated with susceptibility to sepsis and a higher risk of adverse outcomes. Several studies have confirmed that a mutual association between gut microbiota and the host is important for the metabolism of essential nutrients for the organism, for gut development, and the maturation and development of a fully functional immune system. Therefore, depth knowledge of the gut microbiota diversity, composition, and function during various inflammatory conditions and sepsis may provide a comprehensive understanding of the mechanisms behind the pathogenesis of gut-derived infection in diseases and the design of new treatment options (e.g., probiotics or fecal microbiota transplantation). 
Emerging evidence display an important role of gut microbiota and their derived metabolites in modulating the host mucosal immune response and determining the susceptibility to, as well as outcomes of sepsis.