1. Home
  2. / Science and Technology
  3. / Stress on the gut and the biological clock: study reveals how eating after 9 PM can increase constipation, diarrhea, and reduce beneficial microbiota bacteria
Reading time 5 min of reading Comments 0 comments

Stress on the gut and the biological clock: study reveals how eating after 9 PM can increase constipation, diarrhea, and reduce beneficial microbiota bacteria

Written by Carla Teles
Published on 04/05/2026 at 23:32
Be the first to react!
React to this article

Gut stress can become even more intense when eating happens late at night, according to data presented at Digestive Disease Week 2026, which links this habit to more digestive problems and changes in the gut microbiota

Gut stress became the focus of a new scientific analysis presented at Digestive Disease Week 2026, after researchers examined data from thousands of people and found a link between high stress levels, nighttime eating, and worsening digestive symptoms. The study was led by Harika Dadigiri, a resident physician at New York Medical College at Saint Mary’s and Saint Clare’s Hospital, and will be presented on May 4, at 12:30 PM CDT.

According to Science Daily, the results drew attention because they indicate that gut stress can experience an amplified effect when a person consumes a large part of their food after 9 PM. In addition to increasing the chance of constipation and diarrhea, this combination was also linked to a reduction in gut microbiota diversity, an important finding for those who monitor the relationship between digestion, eating routine, and health over time.

What the study discovered about gut stress

The researchers started from a point already known in medicine: chronic stress often unbalances digestion. The novelty was observing how meal times can aggravate this condition, especially among people under high stress loads.

According to the lead author, it’s not just what you eat, but also when you eat. Within this scenario, the study suggests that gut stress can receive a kind of double impact, with damage to both digestive function and the balance of beneficial gut bacteria.

The numbers that stand out most

To explore this connection, researchers analyzed data from over 11,000 participants in the National Health and Nutrition Examination Survey, NHANES. They cross-referenced information on chronic stress, nighttime eating, and intestinal symptoms.

Participants with a high allostatic load score, an indicator of cumulative physical stress based on body mass index, cholesterol, and blood pressure, were more likely to report digestive problems. Among those who consumed more than 25% of daily calories after 9 PM, the risk of suffering from constipation or diarrhea was 1.7 times higher compared to people with lower stress and no late-night eating.

Another data set reinforced the warning

The same pattern appeared in a second set of information, this time with data from over 4,000 people from the American Gut Project. In this group, individuals with high stress levels and nighttime eating habits were 2.5 times more likely to report intestinal problems.

Furthermore, these participants showed reduced diversity in their gut microbiome. This reinforces the idea that gut stress not only affects immediate discomfort but can also be linked to changes in the ecosystem of bacteria involved in digestive function.

Why meal timing can be so impactful

The study fits into a growing area of science called chrononutrition, which investigates how the biological clock interferes with how the body processes food. Within this logic, the timing of a meal can influence as much as the content of the plate.

The research suggests that, during times of stress, late meal times can intensify the effects on the gut-brain axis, the communication network that connects the brain, hormones, nerves, and microbiome. This helps explain why gut stress can become stronger when the habit of eating late is repeated.

What the research cannot yet confirm

The authors themselves make it clear that the study is observational, meaning it does not definitively prove cause and effect. In other words, the data shows a relevant association, but it does not allow for a definitive statement that eating late is the direct cause of intestinal problems.

Even so, the findings reinforce a growing body of evidence on the role of meal timing in digestive health. The study does not close the matter, but it broadens the warning sign about how stress in the gut can be aggravated by recurrent nocturnal habits.

Small habits can make a difference

Dr. Dadigiri herself acknowledges that late-night snacks are common, especially after long and tiring days. Therefore, the study’s message does not appear as an absolute prohibition, but as an invitation to organization.

According to her, small, consistent habits, such as maintaining a structured eating routine, can help promote more regular patterns and sustain digestive function over time. Her statement perfectly summarizes the research’s tone: simple adjustments can have significant weight when **gut stress** is already high and the body enters a very late eating routine.

Why this topic might interest so many people

The study’s strength lies in the fact that it touches on a common combination in modern life. High stress, busy routines, irregular meals, and digestive discomfort are part of many people’s reality, which makes the data especially easy to recognize in daily life.

By linking chronic stress, nocturnal eating, and changes in gut microbiota, the research broadens the discussion about the gut and shows that the problem may not only be in the food, but also in the clock.

What will be presented at Digestive Disease Week

The conclusions will be presented by Harika Dadigiri in the study titled “Beyond Sleep: How Stress and Nocturnal Eating Affect Bowel Habits and Gut Microbiota Diversity, a Multi-Cohort Study”, identified as abstract Mo1769.

The topic gains prominence precisely by showing that **gut stress** can be more complex than it seemed. **When the body is already under pressure and also receives a late food intake, the impact on digestion and microbiota can be greater than many imagine.**

If gut stress can worsen so much with nocturnal eating, are many people treating as a minor detail a habit that has already become a silent part of the problem?

Sign up
Notify of
guest
0 Comments
most recent
older Most voted
Built-in feedback
View all comments
Carla Teles

I produce daily content on economics, diverse topics, the automotive sector, technology, innovation, construction, and the oil and gas sector, with a focus on what truly matters to the Brazilian market. Here, you will find updated job opportunities and key industry developments. Have a content suggestion or want to advertise your job opening? Contact me: carlatdl016@gmail.com

Share in apps
0
I'd love to hear your opinion, please comment.x