5 Ways Gut Health Affects Your Sleep

Gut health and sleep

September 25, 2019

By Dr. Mahmoud Ghannoum

When you don’t sleep well, nothing else really goes well, either. Lack of sleep results in difficulty focusing, mood swings, cravings, daytime fatigue, and poor decision-making, among other symptoms.

Most people look to outside factors like stress and environment when they experience sleepless nights, but there’s one important, internal place you should consider as the cause: Your gut microbiome. Here are five ways your gut health affects your sleep.

Poor sleep upsets your gut.

And it doesn’t take very long: Research tell us that a tiny amount of sleep loss can very quickly alter the composition of your gut microbiome. When you sleep poorly, your gut suffers and can’t do its many jobs efficiently.

It’s not just lack of sleep that does this, either. Fragmented sleep (restless sleep characterized by several frequent, but unnoticeable, awakenings) keeps you from spending adequate time in REM sleep and the deep, restorative stages of sleep. The result? A very unhappy gut microbiome and changes in metabolism, not to mention daytime fatigue that makes you want sugar and caffeine at every turn of the hour.

Your microbiome acts like a “second brain.”

Wait, what? Yep, your microbiome is home to its own bundle of about 100 million nerve cells that communicate constantly with your brain and central nervous system. Your gut helps to regulate hormone production, immune function, digestion, appetite, metabolism, mood, and emotional responses.

The health of your gut microbiome may be linked to mental health, and mental health is connected to sleep. It’s a complex three-way intersection, but research suggests that if you take good care of your gut, you’ll get better sleep and thus improve your mood or mental state of being.

For example, many people who struggle with insomnia also struggle with depression, and both insomnia and depression have been linked to poor gut health. If you grapple with either, try looking to your second brain in addition to your real one.

Your microbiome is regulated by circadian rhythms.

You and every other human has a unique “body clock” or circadian rhythm. This internal 24-hour cycle differs slightly for each person, but serves the same purpose: To determine when we wake up and when we sleep, as well as to regulate many processes in our bodies, such as metabolism.

Recent research has discovered that gut bacteria heavily influences the regulation of this body clock, thus it influences when and how much we sleep. Our gut microbes move around according to a rhythm during the day and night, and therefore influence the circadian rhythms of other organs. Jet lag appears to disrupt how well our microbial communities work, and shift work causes people to adapt to strange sleep patterns, which changed the patterns of microbes in their guts.

Your gut produces sleep hormones.

Out of all the ways your gut health impacts your sleep, this one is probably the simplest (but not less important by any means). Your gut microbiome regulates the production and distribution of many different hormones, including the sleep-inducing ones: dopamine, serotonin, GABA, and melatonin. An unbalanced microbiome can produce unbalanced levels of these hormones, which can negatively affect sleep.

Friendly bacteria may protect against stress.

High stress usually equals poor sleep. Whether you stress over finances, work, school, relationships, or something else, those racing thoughts do no good for your ability to fall asleep and/or stay asleep. There’s a clear connection between stress and gut health, which means a three-way intersection likely exists between stress, sleep, and gut health.

Fortunately, there also seems to be a connection between good gut bacteria and your body’s ability to fend off stress. All that to say: A happy gut equals less stress equals better sleep.

The sleep-gut relationship is a two-way street.

It’s clear that your gut microbiome communicates with the rest of your body, but the opposite is also true. The composition of your gut affects sleep, and your sleep habits affect the composition of your gut. So how do you fix a cycle that includes both poor sleep and unhappy microbes?

For starters, work on your sleep cycle. Try these tips:

  • Go to bed and wake up around the same time every day, even on weekends.
  • Avoid screens as much as possible in the evening hours.
  • Eat lighter meals at night to give your digestive system time to relax before bed.
  • Stay away from sugary foods before bed.
  • Limit your afternoon caffeine consumption.
  • Implement a relaxing evening routine, such as taking a warm shower and reading one chapter of a good book.

While the occasional sleepless night is unavoidable, taking care of your gut and your sleep schedule most of the time should result in quality shut-eye and refreshed mornings.


BIO: Dr. Mahmoud Ghannoum is one of the world’s leading microbiome researchers and the scientist who named the mycobiome, our body’s fungal community. To read more articles from Dr. Ghannoum go to drmicrobiome.com.