Gut jet lag: The surprising link between your body clock and constipation

by Anna Firth

Introduction

Functional constipation (FC) is one of the most common digestive disorders worldwide, affecting sufferers’ quality of life and placing a significant burden on healthcare services. Genes, diet, fluid intake, physical activity and medication are well-recognised contributors to the condition. Unfortunately, for certain individuals, current treatments including dietary fibre, laxatives and prokinetics don’t go far enough, and they struggle with chronic constipation on and off throughout their lives. However, a new factor has potentially been unearthed that might change that: the body’s internal clock.

Methods

Researchers carried out a narrative review¹ with the aim of contributing to a deeper understanding of the causes of FC. They combined evidence from several disciplines including chronobiology (the study of biological rhythms), gut microbiome research and gastrointestinal physiology to develop a new theoretical model called the Chrono-Microbiota-Motility axis.

The review examined how circadian rhythms influence gut bacteria, intestinal movement, the gut barrier and inflammation. It also explored whether lifestyle interventions that restored circadian rhythms could improve bowel function.

Key results

The review proposes that healthy bowel function depends on the synchronisation of three systems: the body’s internal circadian clock; the daily activity of the gut microbiome; and normal intestinal movement. When these systems become dysregulated and out of sync, the authors suggest this creates “gut jet lag”, which may contribute to FC.

The review highlights several key mechanisms including:

1. Disruption of the normal daily production of short-chain fatty acids by gut bacteria may reduce signals that stimulate bowel movements.

2. Disturbance of the gut’s own biological clock may reduce the strong morning contractions that normally help gut motility.

3. Circadian disruption may lead to intestinal permeability (aka “leaky gut”), increasing low-grade inflammation and making the gut more sensitive.

The authors argue these changes may explain why people with irregular routines, including shift workers and those with inconsistent eating patterns, are more likely to experience digestive issues.

What does this mean?

The researchers have developed a theory, rather than carrying out a clinical trial, but the results of the review are important because they reinforce the importance of regular daily habits for digestive health.

The review suggests that supporting the body’s natural circadian rhythm (chronotherapy) could become part of constipation management alongside established advice on fibre, fluids and physical activity.

Potential strategies to support the gut’s body clock include:

· Maintaining consistent sleep and wake times. Regular sleep-wake patterns help stabilise the production of cortisol and melatonin which supports the syncing of the gut’s rhythms.

· Eating meals at regular times each day. Eating provides the most powerful signal to synchronise the gut’s biological clock.

· Avoiding late-night eating where possible. This sends a false “feeding” signal to the intestine when it should be at rest.

· Increasing exposure to daylight during the morning. Intestinal motility is strongest during the day.

· Reducing exposure to blue light before bedtime. Artificial light interferes with melatonin production.

· Considering time-restricted eating (TRE) where appropriate and clinically suitable.

The review encourages consideration of daily routines including light exposure, sleep patterns and meal timing when assessing persistent constipation. These lifestyle factors may offer additional opportunities for personalised support. Melatonin, probiotics and prebiotics could also be considered to help with symptoms and the restoration of digestive balance. The study authors suggest using questionnaires to assess the risk of gut jet lag: Information about sleep quality, food intake alongside timings can help highlight irregular sleeping and eating patterns, as well as skipping meals or eating late at night.

Limitations

The review presents an interesting hypothesis but it is important to recognise its limitations. It is not based on a single clinical study and cannot prove that disruption directly causes constipation. Most of the evidence comes from animal studies or observational research, where cause and effect cannot be established. Many of the proposed interventions, including paying attention to daily rhythms (chronotherapy) and time-restricted eating (TRE), require larger randomised controlled trials before they can be routinely recommended specifically for constipation.

In addition, constipation is multi-factorial. A number of other causative factors could be at play including medical conditions, medications and diet. Gut jet lag will not be the culprit in every case.

Conclusion

This review introduces a novel way of thinking about constipation by focusing on the timing of biological processes rather than diet or bowel function alone. The concept of “gut jet lag” suggests modern lifestyles may disrupt the relationship between the body’s internal clock, the gut microbiome and intestinal motility. While more research is needed to confirm this theory, the review makes a good case for the beneficial effects of maintaining regular sleep, mealtimes and daily routines as part of a healthy lifestyle. Circadian-based approaches could be valuable low-risk additions to support existing FC management.

References:

¹ Li J, Yu K, Sui X, Deng H, Leng Y, Liu T. Gut jet lag: how circadian rhythm disruption undermines the Chrono-Microbiota-Motility axis and induces functional constipation. Front Nutr. 2025 Oct 2;12. doi:10.3389/fnut.2025.1678482