Fig. 2

Intestinal microbiota in health and critical illness. The microbiota in a healthy individual is a diverse ecosystem with beneficial and commensal bacteria and low abundances of opportunistic pathogens, which are not harmful in small numbers. As a result of certain therapies, such as antibiotics, the microbial composition can be disrupted. The intestinal microbiota of critically ill patients is less diverse and contains more opportunistic pathogens and less beneficial and commensal bacteria