Phase separation crucial for gut bacteria survival and fitness.

Yale researchers have discovered that the beneficial gut bacterium Bacteroides thetaiotaomicron responds to carbon limitation by sequestering a portion of the molecules for an essential transcription factor within a membrane-less compartment, which increases its activity and modifies the expression of hundreds of bacterial genes, including several that promote gut colonization and control central metabolic pathways in the bacterium. These findings reveal that "good" bacteria use sequestration of molecules into membrane-less compartments as a vital strategy to colonize the mammalian gut, and could help spur the development of new probiotic therapies for gut health.