Host/microbiota interactions in health and diseases-Time for mucosal microbiology!

Abstract

During the last 20 years, a new field of research delineating the importance of the microbiota in health and diseases has emerged. Inappropriate host-microbiota interactions have been shown to trigger a wide range of chronic inflammatory diseases, and defining the exact mechanisms behind perturbations of such relationship, as well as ways by which these disturbances can lead to disease states, both remain to be fully elucidated. The mucosa-associated microbiota constitutes a recently studied microbial population closely linked with the promotion of chronic intestinal inflammation and associated disease states. This review will highlight seminal works that have brought into light the importance of the mucosa-associated microbiota in health and diseases, emphasizing the challenges and promises of expending the mucosal microbiology field of research.

Fig. 1. Host/microbiota interaction at the mucosal surface.

At steady state (left part), the mucus layer keeps the bacterial community at a safe distance, while select symbionts favor maturation of the mucosal immune system by interacting with the host epithelium. In response to various stressors (right part), the mucus layer is altered in a way that leads to microbiota encroachment and chronic inflammatory diseases. Such altered host/microbiota relationship can be reversed by fiber-rich diet consumption, Akkermansia muciniphila administration or targeted mucosal immunization.