Molecular mechanisms underpinning circadian host-gut microbe interactions
Food intake introduces both nutrients and food-borne pathogens into the gut, therefore the upregulation of both metabolism and components of innate immunity during feeding is crucial for gut function and pathogen defence during this period of acute pathogen exposure42. Yet what are the major mechanisms underpinning this process? Whilst this field of research is in its infancy, a number of recent experimental studies on murine models outline some of the mechanisms underpinning circadian host-gut microbe interactions. These mechanisms generally involve cyclical interactions between food intake, components of the immune system including antimicrobial peptides (AMPs) and the antibody secretory Immunoglobulin A (SIgA), and certain mucosal commensals (Fig. 1).