Inflammatory bowel disease more common in night owls

Inflammatory bowel disease(IBD) refers to 2 conditions that present with chronic inflammation in the gut. Crohn’s disease affects any part of the gut while ulcerative colitis involves only the colon/rectum.

Over time, inflammatory bowel disease causes substantial damage to the gut. Symptoms of IBD include:

  • Pain/bloating
  • Fatigue
  • Bloody stools
  • Chronic diarrhea
  • Nutritional deficiencies

People with IBD often experience episodes called flares. As a result, people often feel perfectly fine…until they don’t. And then, it’s misery.

While we don’t have a firm grasp on what causes IBD, circadian rhythms play a role. Here we have a review on circadian rhythms in IBD. In addition, this series of papers show that the circadian rhythm in innate lymphoid cells type 3 are dampened in people with IBD.

And then we have this paper, showing that people who are night owls are more likely to have IBD than early birds. In fact, they are also more likely to develop Type 2 diabetes, cardiovascular disease, obesity, and certain types of Cancer. Other data shows night owls are more likely to have poor mental health as well.

There’s good reason for this, and it’s not genetic.

Chronotype and inflammatory bowel disease

Most people feel that being a night owl is a genetic destiny. But this isn’t quite true, at least not for everyone. While there are genetic predispositions towards being a night owl, environment plays a huge role too.

This is just how biology plays out. Your fate is ultimately determined by the interaction between your genes and environment. And for most chronic diseases, the environment plays a much larger role than genes. By most estimates, 70-90 percent.

Granted, we don’t know the specific environmental factors for most chronic disease, but we do know that those that disrupt circadian rhythms are really important. In night owls, these behaviors are simply more prevalent.

Since night owls are sort of forced in to living in an early bird World, they are more likely to change their sleeping habits on the weekend or work night shift. This habit was recently shown to double the risk of cardiovascular disease.

Night owls are also more likely to eat on an erratic schedule, and less likely to eat fruits and vegetables. Furthermore, they are more likely to consume energy drinks to get by and consume a higher fat diet, a diet that disrupts circadian rhythms.

How circadian disruption promotes inflammatory bowel disease

So how does disruption of circadian rhythms promote IBD? This image is a good start:

Inflammatory bowel disease
Image Source

Circadian rhythms take charge of automatic processes throughout the body, and digestion is no different. But digestion is much more than simply digesting and absorbing our food.

Eating is an inflammatory event, whether you’re eating fruits and vegetables or a steak. To prepare for this onslaught of foreign material, the gut has to batten down the hatches.

The cells in the gut have to coordinate cell turnover such that it doesn’t happen while we eat. Cells in the gut secrete mucus to prevent mechanical and chemical damage to the intestinal wall. It also keeps bacteria from coming in to close contact.

The function of immune cells waxes and wanes throughout the day, and immune tolerance prevents us from reacting to properly digested components of food. But wait, there’s more:

Antimicrobial peptides provide a chemical barrier within the mucus layer that keeps bacteria, both good and bad, away. Tight junction proteins anchor cells in the gut together so that they don’t become “leaky”.

Members of a healthy microbiome help maintain this layer and degrade it, while crowding out the bad guys. They also have their own circadian rhythm, varying in abundance and distance from the intestinal wall throughout the day.

All of these factors, and many more, are regulated by circadian rhythms. The gut doesn’t have a watch, it depends on environmental cues to know when and what to do.


Nearly every aspect of your gut health is under circadian regulation. For optimal gut health, it’s imperative that these systems all operate on the same time.

Unfortunately, for night owls, they send mixed messages. As a result, they tend to have tissue-specific circadian disruption that leads to the following problems:

  • A thinner mucus layer
  • Increased inflammation
  • Increased “leaky gut”
  • An altered microbiome
  • Increased systemic inflammation

Ultimately, addressing lifestyle corrects these problems for many. The first step is to identify the behaviors disrupting your circadian rhythms. The second step is to develop a schedule that works with you, your occupation, and your lifestyle to help build resilience in your gut.

Want to know how to switch from being a night owl? Check out this FB Live video I did for the FB page. I cover the 2 basic principles of light and food that can help shift you towards a healthier schedule. Check it out:

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