LAUSR

Purpose of review Maintaining gut barrier defenses, modulating immune responses, and supporting the role of commensal microbiota are major factors influencing outcome in critical illness. Of these, maintaining a commensal ‘lifestyle’ and preventing the emergence of a virulent pathobiome may be most important in reducing risk of infection and multiple organ failure. Recent findings The polymeric formulas utilized for enteral nutrition in the ICU are absorbed high in the gastrointestinal tract and may not reach the microbial burden in the cecum where their effect is most needed. The provision of a few select probiotic organisms may be insufficient to refaunate the gut and establish a ‘recovery pattern,’ propelling the patient toward health and homeostasis. Use of fecal microbial transplantation (FMT) appears to be a more successful strategy for replenishing the intestinal microbiome and maintaining its commensal phenotypic expression. Summary FMT has become an attractive option to mitigate multiple organ dysfunction in the ICU. This article discusses the physiology, rationale, early experience, and expectations for such therapy in the critically ill patient.