Late-Night Eating and Sleep Habits Linked to Gut Barrier Damage and Metabolic Disease Risk in Adults with Obesity

A team led by UTHealth Houston has published findings in iScience tying together three things that are usually studied apart: when adults with obesity sleep, when they eat, and what is happening in their gut. The work was led by Faraz Bishehsari, MD, PhD, a professor and director of the Gastroenterology Research Center in the Department of Internal Medicine at McGovern Medical School at UTHealth Houston.

The researchers looked at circadian behaviors in adults with obesity and how those behaviors relate to metabolic health. They examined two things: chronotype, meaning whether a person naturally prefers to wake early or stay up late, and the timing of food intake. Participants with a later chronotype, the so-called night owls, tended to have more risk factors for metabolic syndrome than early chronotypes, or early birds. Metabolic syndrome is a cluster of conditions that raises the risk of heart disease, stroke, and Type 2 diabetes.

The highest metabolic risk appeared in people who combined the two patterns: a late chronotype and late-night eating. The authors suggest that a mismatch between the body's internal clock and daily behavior may contribute to disease risk, with the gut microbiome and the intestinal barrier as part of the route.

To look at the gut more closely, the team built a measure they call a Metabolic-Inflammatory Score, intended to capture how the body responds to immune and metabolic changes. People with higher metabolic risk showed signs of what is commonly called leaky gut. In that state, substances normally kept inside the intestines pass into the bloodstream, where they can trigger inflammation and affect other parts of the body.

The researchers also asked whether improving the microbiome could strengthen the barrier. Participants whose gut barrier function improved after a microbiome-targeted intervention also showed an increase in beneficial bacteria that produce short-chain fatty acids. The authors read this as a sign that the microbiome may be a modifiable pathway linking circadian behaviors to metabolic health.

Bishehsari framed the work around timing. "We know that what we eat matters for our health, but our findings suggest that when we eat is also important," he said, adding that the gut microbiome and intestinal barrier may help explain how disrupted daily rhythms connect to metabolic inflammation. He said he and his colleagues wanted to take the question beyond the clinic and look at how eating patterns and sleep play out in everyday life.

Because meal timing and other circadian behaviors can potentially be changed, he said, understanding these relationships could open new ways to prevent or manage metabolic disease through lifestyle changes and gut-targeted interventions. The authors point to modern lifestyles that increasingly strain natural sleep and eating rhythms, and say diet quality alone may not be the whole picture.

The study involved researchers from several institutions. Besides Bishehsari, UTHealth Houston authors include Xiangsheng Huang, Connor Cheek, and Mahboobeh Mahdavinia. Collaborators came from Rush University Medical Center (Edena Khoshaba, Ankur Naqib, Maliha Shaikh, and Ali Keshavarzian), Northwestern University (Mohamed Abdel-Mohsen), and the University of Nebraska (Heather Rasmussen).

What remains open is whether changing the pattern changes the outcome. Bishehsari said future research will test whether therapies that improve circadian alignment or strengthen the gut microbiome can reduce inflammation and lower the risk of metabolic disease.