“…Our data also build upon previous findings that indicate nutritional status and feeding-associated cues potently alter the magnitude of IgA secretion and microbiota-associated oscillations. Indeed, both long-term undernutrition or chronic overnutrition can alter the generation of IgA responses in the intestinal tract, suggesting a dynamic interplay between nutrition, circadian rhythms and mucosal antibody responses and hostcommensal mutualism (9,14,15,20,21,23,25,28,29). More broadly, these findings suggest circadian IgA regulation of the microbiota may act to promote mutualism, metabolite availability and metabolic health, which together with recent advances (49), suggest IgA acts to determine host exposure to microbially-derived metabolites.…”