Bacterial Translocation from the Gut to the Distant Organs: An Overview

Under healthy milieus, the intestinal barrier is generally very dynamic and effective, with luminal side being heavily infested with a wide variety of gut microbes while the basolateral side remains virtually sterile. However, certain conditions such as abnormal exposure to toxins, drugs, pathogens etc. or a state of hyper-inflammation due to disease conditions may weaken or destabilize the integrity of gut epithelia. A perturbed gut integrity and permeability ("leaky gut") may lead to microbial (bacterial) translocation, and the eventual leakage of bacteria or their metabolites into the circulation can make the host susceptible to various types of diseases via inducing chronic or acute inflammatory response. Key Message: Given a close association with gut integrity, bacterial translocation and inflammatory responses have recently emerged as a clinically important research field and have unveiled novel aspects of gut microbial ecology and various gastrointestinal, metabolic, and lifestyle diseases. This review aims to describe the significance of a healthy gut barrier integrity and permeability, as well as the factors and consequences associated with a compromised gut barrier, while discussing briefly the dietary approaches including probiotics and prebiotics that could ameliorate gut health by restoring gut environment and barrier integrity, thereby preventing bacterial translocation.