1) The adaptive significance of gut microbial oscillations
In which evolutionary contexts do we expect the evolution of gut microbial oscillations, and when would we expect food intake and the gut microbiome to entrain host immunity? Based on f from murine models, one predicts that food intake, metabolic requirement, and pathogen exposure are synchronised to peak at the start of the active phase (i.e., at dusk for mice). Such correlation between feeding, metabolic and immune requirements is expected to be the norm, given that feeding introduces both nutrients and pathogens to the gut. Hence, hosts appear to have co-opted the gut microbiota to mediate both metabolic and innate immune function simultaneously.