Introduction: Sepsis is a life-threatening syndrome which can progress to multiple organ dysfunction with high mortality. Intestinal barrier failure exerts a central role in the pathophysiological sequence of events that lead from sepsis to multiple organ dysfunction. The present study investigated the role of hydrocortisone (HC) administration and fecal microbiota transplantation (FMT) in several parameters of the gut barrier integrity, immune activation, and survival, in a model of polymicrobial sepsis in rats. Methods: Forty adults male Wistar rats were randomly divided into four groups: sham (group I), cecal ligation and puncture (CLP) (group II), CLP þ HC (2.8 mg/kg, intraperitoneally single dose at 6 h) (group III), and CLP þ FMT at 6 h (group IV). At 24 h post-CLP, ileal tissues were harvested for histological and immunohistochemical analyses while endotoxin, IL-6, and IL-10 levels in systemic circulation were determined. In a second experiment the same groups were observed for 7 days for mortality, with daily administration of hydrocortisone (group III) and FMT (group IV) in surviving rats. Results: HC administration and FMT significantly reduced mortality of septic rats by 50%. These interventions totally reversed intestinal mucosal atrophy by increasing villous density and mucosal thickness (mm, mean AE SD: