Circadian reprogramming by timed sodium intake reveals transcriptional pathways of daily salt handling in the colon

Circadian misalignment of the feeding behavior and the terrestrial cycle is associated with obesity and metabolic perturbations. However, it remains unclear whether the quantity and timing of dietary salt intake influence temporal sodium handling and blood pressure regulation. Here, we demonstrate that the colonic mineralocorticoid receptor (MR) and peripheral clock affect the daily sodium absorption and blood pressure variations. Genes related to sodium handling display diurnal rhythms in synchrony with the daily rhythms of aldosterone and the colonic circadian clock. Cistromic analysis substantiated the overlap of occupancy between the MR and brain and muscle ARNT-like 1 (BMAL1). Diurnal oscillation of aldosterone and peripheral clocks, as well as blood pressure, was robustly driven by nighttime feeding of a low-salt diet but markedly disrupted by daytime feeding of a high-salt diet in nocturnal mice. These findings delineate the colonic temporal sensing of dietary sodium abundance and highlight the transcriptional mechanisms of daily salt handling and blood pressure variations.