Functional Plasticity in gut microbe-host interactions

In recent years, there has been a scientific awakening to the impact of the gut microbiota on host physiology. It is currently clear that the microbiota has profound effects on host physiology, yet studies on their causal effects, and functional molecules at play are still in their infancy. We recently characterized a phase-variable system in the gut bacteria - Bacteroides fragilis, which responds to the environment and dictates bacterial functionality (Ben-Assa*, Coyne*, et. al., Nucleic Acids Research, 2020, and unpublished data). Phase-variation mechanisms and alike, allow the bacteria to change their functionalities in a reversible manner, enabling bacterial functional plasticity. I will present the concept of such “functional plasticity” in gut microbe-host interactions and the potential mechanisms involved, with a focus on bacterial immune-modulation. Gut bacterial functional plasticity is fascinating as it allows the bacteria to alter their interactions with the host in their ever-changing and dynamic gut ecosystem. Studying the mechanisms of these systems will enable unveiling the causality dimension of gut microbe-host interactions and the molecules involved.