{"id":1421,"date":"2026-06-23T09:09:00","date_gmt":"2026-06-23T07:09:00","guid":{"rendered":"https:\/\/www.nutrimedia.info\/?post_type=news&p=1421"},"modified":"2026-06-11T18:10:53","modified_gmt":"2026-06-11T16:10:53","slug":"evening-meals-gut-clock","status":"publish","type":"news","link":"https:\/\/www.nutrimedia.info\/en\/news\/les-repas-nocturnes-horloge-intestinale\/","title":{"rendered":"Late-night meals desynchronise the gut's circadian clock"},"content":{"rendered":"

Eating \u00about of sync\u00bb with your body clock, particularly at night, doesn't just disrupt the central clock in the brain: night-time meals also desynchronise the circadian clocks of different intestinal cells, with potential consequences for digestive motility and the risk of gastrointestinal disorders in shift workers and frequent travellers.<\/strong><\/p>\n\n\n\n

A recent study conducted at UT Southwestern Medical Center, published in Proceedings of the National Academy of Sciences<\/em> (PNAS), shows that eating at an unusual time of day does indeed profoundly desynchronise the internal clocks of intestinal wall cells, and highlights a new culprit: \u00abpacemaker\u00bb cells that refuse to reset to the new rhythm<\/strong> food<\/strong>. In other words, regular evening meals are real circadian disruptors.<\/p>\n\n\n\n

The circadian rhythm: much more than just a sleep clock<\/h2>\n\n\n\n

Circadian rhythms correspond to cycles of approximately 24 hours regulating sleep, body temperature, hormone release... but also the activity of the digestive tract.<\/strong> These rhythms are orchestrated by a central clock in the suprachiasmatic nucleus (SCN) of the hypothalamus, synchronised primarily by environmental light.<\/p>\n\n\n\n

It is now known that most peripheral tissues possess their own autonomous clocks, capable of maintaining rhythmicity even in the absence of central signals, but highly sensitive to local synchronisers such as meal times. In the intestine, these peripheral clocks influence motility, enzyme secretion, epithelial renewal, absorption, and certain components of the local immune response.<\/p>\n\n\n\n

A real-time study of gut clocks during evening meals<\/h2>\n\n\n\n

To understand how nighttime meals disrupt the gut, Obata and colleagues used genetically modified mice that expressed a bioluminescent reporter of the key circadian gene. Per 2<\/em> (Per2::Luc), developed in Joseph Takahashi's laboratory. This approach allows for real-time, ex vivo monitoring of the circadian activity of different cell types through bioluminescence measurement.<\/p>\n\n\n\n

Researchers have focused on five main cell populations in the muscularis externa<\/em>\u00a0enteric neurones, enteric glial cells, smooth muscle cells, intestinal macrophages, and interstitial cells of Cajal (ICCs). Under standard conditions (mice fed overnight, their normal period of activity), each of these populations exhibits robust and self-sustained circadian oscillations that are aligned with each other.<\/p>\n\n\n\n

When diet shifts... and clocks go haywire<\/h2>\n\n\n\n

The team then subjected the mice to a \u00abdaytime restricted feeding\u00bb protocol: food was only accessible for 4 hours during the day, which for these nocturnal animals is the equivalent of a \u00abnight-time meal\u00bb for humans. Under this altered regimen, the authors observed that enteric neurons, glial cells, smooth muscle cells, and muscle macrophages gradually adjusted the phase of their clocks to re-align with the new feeding schedule.<\/p>\n\n\n\n

In contrast, the interstitial cells of Cajal hardly modified their circadian phase: they continued to oscillate to their initial rhythm, as if the food signal was not a powerful enough synchroniser for these cells. Result: a persistent desynchronisation between the clocks of different cell populations in the gut, which persists even after several weeks of phased feeding.<\/strong><\/p>\n\n\n\n

Interstitial cells of Cajal: alternative pacemaker cells<\/h2>\n\n\n\n

ICC are specialised cells, found in the musculature of the digestive tract, which generate \u00abslow waves,\u00bb electrical waves that orchestrate rhythmic contractions of the smooth musculature and the progression of food boluses. They form a functional network acting as a true pacemaker for gastrointestinal motility.<\/p>\n\n\n\n

In the context of this study on nighttime meals, these ICCs behave like \u00abrogue pacemaker cells\u00bb: they retain their original circadian phase while other cells synchronise to the new feeding pattern. This resistance to entrainment by food means that digestive motility can remain aligned with the old \u00abinternal clock\u00bb, while feeding and neuronal stimuli follow a new temporal pattern.<\/p>\n\n\n\n

\"Evening<\/figure>\n\n\n\n

Towards an \u00abinternal gut jet lag\u00bb<\/h2>\n\n\n\n

The desynchronisation between cellular clocks translates concretely into a decoupling between the timing of contractions, that of secretion and absorption, and local neuronal and immune signals. This \u00abinternal intestinal jet lag\u00bb could manifest through symptoms such as slowed transit, post-prandial discomfort, bloating, or even increased sensitivity to visceral pain stimuli.<\/p>\n\n\n\n

The authors suggest that analogous situations of desynchronisation could occur in humans during shift work<\/a>, with repeated jet lag or chronic night eating.<\/strong> These late-night meal contexts are already associated with an increased prevalence of functional digestive disorders and inflammatory pathologies, which strengthens the biological plausibility of the link.<\/p>\n\n\n\n

Shift work, evening meals, jet lag and digestive health<\/h2>\n\n\n\n

Several studies show that Night or shift workers have a higher frequency of gastrointestinal symptoms<\/strong> (abdominal pain, constipation, diarrhoea, reflux), as well as an increased risk of irritable bowel syndrome and other functional disorders. These clinical observations are accompanied by experimental data showing that circadian desynchronisation affects intestinal permeability, epithelial renewal and microbiota composition.<\/p>\n\n\n\n

A recent review highlights that the disruption of circadian clocks and the microbiota<\/a> Among shift workers, it contributes to low-grade inflammation, metabolic disorders, and digestive symptoms. Practical recommendations are emerging, including stabilising sleep schedules, optimising light exposure, and a more regular and better-timed structure to eating patterns. <\/p>\n\n\n\n

Chrononutritional strategy pathways<\/h2>\n\n\n\n

Even if the full translatability of murine results still needs to be demonstrated, several broad lines emerge for the practice of nighttime meals:<\/p>\n\n\n\n