Interactions between Intestinal Microflora/Probiotics and the Immune System.

The digestive tract is home to millions of microorganisms and is the main and most important part of bacterial colonization. On one hand, the abundant bacterial community in intestinal tissues may pose potential health challenges such as inflammation and sepsis in cases of opportunistic invasion. Thus, the immune system has evolved and adapted to maintain the symbiotic relationship between host and microbiota. On the other hand, the intestinal microflora also exerts an immunoregulatory function to maintain host immune homeostasis, which cannot be neglected. In addition, the interaction of either microbiota or probiotics with immune system in regard to therapeutic applications is an area of great interest, and novel therapeutic strategies remain to be investigated. The review will elucidate interactions between intestinal microflora/probiotics and the immune system as well as novel therapeutic strategies.