If you’ve ever experienced unpleasant stomach issues or your appetite’s been off the day after a restless night, you’ve felt the connection between gut health and sleep. You know that both sleep and gut health are keys to wellness on their own. But it turns out, the relationship between the two can also play a major role.
When it comes to sleep, generally, we think about what’s happening in our brains. But we also need to consider the microbiome.
What is the microbiome?
The microbiome is essentially the world within us that helps us function, including the bacteria, fungi, viruses, and other microbes that live inside us. These microbes perform a vast array of functions, affecting our immune system, digestion, mood, energy, and of course, sleep.
Our microbiome is individual to each of us. Though the core of it is formed when we’re born and in the early years of life, it’s constantly affected by our diet, exposure to toxins in our environment, medications, and other inputs. Different parts of the body, such as the skin, mouth, and gut, have their own set of microbes — similar to how a single state has different cities, each with its own community of residents.
What does the gut have to do with sleep?
Those “gut feelings” that sometimes guide our actions illustrate the connection between the microbiome and the brain, which research confirms. Known as the gut-brain axis, this relationship involves signaling back and forth between the two via the nervous system.
“The gut bacteria, known as the gut microbiome, all contain their own DNA,” says physician and registered dietician Dr. Amy Burkhart. “Historically, we’ve thought of our human DNA as the roadmap for all that happens in our body. But we now know that the gut bacteria's DNA also influences how the human body functions. Because there’s more bacterial DNA in our bodies than human DNA, the bacteria's influence on our overall health may be more significant than we could ever imagine. This includes the effect the gut bacteria have on sleep.”
Good sleep helps the gut …
Part of the reason gut health has received so much attention in recent years is because of its significance. Poor gut health is associated with a host of serious illnesses; along with inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, gut health is also linked to diabetes, liver diseases, heart disease, and several types of cancer.
Though many factors affect gut health, sleep can make a real difference — positively and negatively.
“Studies have found that sleep deprivation can impact the gut microbes after just two days of getting less sleep then we need,” says Sandy Soni, gut specialist dietitian at the Gut Health Clinic in London. “Sleep deprivation can also increase inflammation and stress hormones in the body.”
The same poor habits that upset sleep also can disrupt gut health. “Anything that negatively impacts sleep would negatively impact gut health since the communication between the gut and brain is bidirectional,” Burkhart explains. She also notes that things like chronic stress, little or no exercise, sugar, processed foods, alcohol, and exposure to caffeine and/or blue light too close to bedtime are all problematic for gut health.
But this connection also gives us another important reason to work on our sleep hygiene. A few simple steps — such as creating a nighttime routine and spending more time outdoors — can go a long way toward improving both sleep and gut health.
… and a healthy gut helps with sleep
Just as good sleep helps the gut, a healthy microbiome can lead to more and better sleep.
“Studies have found that increased microbiome diversity is correlated with longer sleep times and better sleep efficiency,” Soni says. “So feeding the gut microbes well could lead to a reduction in sleep issues and improved mood.”
One way a healthy gut helps is by managing our internal clock. “A study at the University of Missouri found the gut microbiome to be a major player in sleep regulation,” Burkhart says. “The gut bacteria regulate circadian rhythms, and thereby improve sleep quality.”
How to improve both gut health and sleep
The good news is many of the habits you’re likely already working on can aid your gut health and sleep — and helping one means helping both. Some of these include:
- Eat a healthy diet. “Eating a whole-foods diet low in processed foods, which can irritate the gut, and decreasing or eliminating refined sugars has been shown to affect the gut microbiome positively,” Burkhart says. Also, getting a diverse array of plant foods, such as a variety of vegetables, fruit, nuts, seeds, and eating both pre- and probiotic foods are beneficial, Soni notes.
- Get plenty of protein. New research suggests protein in the diet may boost sleep quality.
- Move often. Getting regular exercise benefits both the gut and sleep. Aim for at least 30 minutes per day.
- Manage stress. “Develop a daily stress-reduction routine,” Burkhart advises. “Breathing exercises, meditation, reading, journaling, or spending 20 minutes in nature are all options. Less stress equals a healthier microbiome and improved sleep quality.”
- Stay hydrated. Drinking enough water helps both gut health and sleep, research shows.
Most importantly, if you slip up with your nutrition or sleep, don’t worry. Our bodies are resilient. Think of this as a blueprint to better overall health to tweak as needed to best suit your lifestyle.