How to improve gut health and why it matters

Key takeaways

A large portion of the immune system is located in the GI tract, and maintaining a healthy gut is crucial for immune function, potentially affecting allergies, depression, and diseases like cancer.
The gut microbiome plays a significant role in digestion, immune protection, disease prevention, weight management, inflammation control, and vitamin production, influencing overall health.
Unhealthy gut health, or a “leaky gut,” can lead to increased intestinal permeability, allowing harmful substances into the bloodstream. Some causes include poor diet, stress, and antibiotics. Symptoms may include chronic diarrhea, bloating, and fatigue.
Improving gut health involves changing diet to include high-fiber, vitamin-rich foods and fermented foods, reducing stress, exercising, getting quality sleep, and treating underlying health conditions.

Curious how healthy you are? Well you may not need to go any further than your own stomach to find out. While you may think of bacteria as a bad thing, the good bacteria in your gut are extremely important to your well-being. It may surprise you how much gut health can affect the entire body.

A large portion of your immune system actually lives in your GI tract, according to research done at the Johns Hopkins Medical School. Studies show that maintaining a healthy gut is essential for immune homeostasis, that your gut can affect the allergies you experience, and an unhealthy gut may be linked to diseases like depression and cancer.

“The gut is the source of where all energy to the body comes from,” says Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, CA. “You can tell how the body is functioning as a whole based on the gut.”

To understand more, you need to know what gut microbes are and how what you eat can impact your overall health.

How gut health affects the whole body

Your gut microbiome refers to the bacteria and other microorganisms that live in the digestive tract, explains Leslie Bonci, MPH, RD, CSSD, LDN, author of the American Dietetic Association Guide to Better Digestion and founder of nutrition consulting company Active Eating Advice.

“The microbiome has a role to play in controlling digestion, protecting the immune system, protecting against other diseases, may have a role to play in weight management, and can help to control inflammation,” explains Bonci. “These bacteria also produce vitamins B12, thiamine, riboflavin, and vitamin K, which is important to help the blood clot.”

Gut bacteria are also important for drug metabolism and increasing bioavailability of medications (or the proportion of a drug that enters the circulation when you take medicine).

If the microbiome in your gut is not as diverse as it should be—meaning, there’s not enough variety of beneficial bacteria—the risk of certain diseases such as Type 1 diabetes, rheumatoid arthritis, muscular dystrophy, multiple sclerosis and fibromyalgia may be higher, explains Bonci.

Also, having unhealthy gut bacteria can be a bad thing for the gut overall, too. Trimethylamine N-oxide (TMAO) is a compound formed in your body after you eat foods that contain a substance called choline. Red meat and eggs are big sources of choline, explains Dr. Bedford. “Bad bacteria in your gut can also produce choline, which leads to the increase of TMAO,” he says. “Too much TMAO can be related to atherogenesis, which is the buildup of fatty plaque in the arteries, which is unhealthy.”

“Bad gut bacteria can also increase the risk of blood clots,” explains Bonci. “Studies being done to determine if altering the gut microbiota can lower cholesterol levels, too.”

What causes a leaky gut?

An unhealthy gut is also known as a leaky gut. “A leaky gut occurs when the space between the cells of the small intestine colon are separated, and some of the contents that should remain in the intestine slips through the cracks of the cells and finds its way into the blood stream,” explains Dr. Bedford. It can also be referred to as increased intestinal permeability. “This may include food particles that can result in immune reactions, as well as toxic chemicals produced by microbes, which results in inflammation and impaired gut function,” explains Bonci.

What causes a leaky gut? According to Bonci, the following may contribute to a leaky or unhealthy gut:

Poor diet
Low levels of iron, vitamin A, and vitamin D
Stress
Antibiotics

Symptoms of an unhealthy gut

There isn’t one exact symptom that would diagnose a leaky gut, but there are lots of signs that you may have one. These signs include:

Chronic diarrhea
Constipation
Bloating
Heartburn
Fatigue
Headaches
Skin problems
Joint pain
Inflammation

How to diagnose a leaky gut

If you’re experiencing one or more of these signs, consult with a gastroenterologist, a doctor who is specially trained to manage diseases of the digestive tract, for a diagnosis. There’s no one test to diagnose an unhealthy gut, but your gastroenterologist may order the following assessments: a lactose/mannitol test, a parasite test, a bacterial dysbiosis test, or a food intolerance/allergy test.

How to improve gut health

Don’t fret if you do have a leaky or unhealthy gut—there are things you can do to improve the issue.

1. Change your diet

Start with your diet. Bonci recommends eating a variety of high-fiber foods, which help protect the mucus layer of the intestine. Try adding some beans, lentils, peas, berries, or nuts into your diet. “Fibrous foods help to promote biodiversity within the gut itself, explains Dr. Bedford. “This will also help to cut down on bad products that may accumulate within the gut, like choline.”

“You’ll also want to eat foods that contain vitamin D, to protect against gut permeability, and vitamin A to prevent deficiency,” says Bonci. To get vitamin D try egg yolks, tuna, beef liver, or sardines. “Fish is good for the gut as well because it contains good fats and is a good source of protein, which adds to the biodiversity of the gut,” says Dr. Bedford. For your vitamin A needs turn to vegetables like carrots, squash, sweet potatoes, and spinach.

Foods that contain probiotics like pickled or fermented foods are healthy for the gut as well. “These foods again increase the bacterial diversity in the gut itself, which helps with overall health,” explains Dr. Bedford.

To summarize, here are four types of foods that heal your gut:

High-fiber foods like beans, lentils, peas, berries, nuts
Vitamin D-rich foods like egg yolks, tuna, beef liver, sardines
Vitamin A-rich vegetables like carrots, squash, sweet potatoes, spinach
Pickled or fermented foods like kimchi, sauerkraut, kombucha

Wondering what foods to avoid? According to Bonci, foods with these characteristics may not be good for the digestive system:

Low fiber
Excess alcohol
Sugary beverages
High fat meals
Foods containing sugar alcohol, such as sugar-free gums and mints (can cause bloating and diarrhea)
Caffeine in large quantities (can cause more frequent bowel movements)
Carbonated beverages (can cause bloating)
Non-fat foods
Excessive red meat (can increase the levels of TMAO)

A food elimination diet or a food allergy test, from a gastroenterologist or immunologist can also help identify foods that aren’t healthy for your gut specifically. “This can help identify which foods are causing problems,” explains Dr. Bedford.

2. Add in a probiotic

Probiotics are live organisms, like bacteria and yeast, that have health benefits. You can find probiotics in fermented foods such as certain yogurts, kefir, kombucha, sauerkraut, pickles, miso, kimchi, and more. If you’re not getting enough of these healthy bacteria through your diet, you may want to consult with your healthcare provider about adding a probiotic supplement into your daily routine.

“You have trillions of bacteria in the gut—more bacteria than cells in your body in fact,” explains Dr. Bedford. “It’s important that you have a large biodiversity of bacteria. Probiotics give you a higher concentration of live microorganisms that will live in the gut, which increases the biodiversity of the bacteria.” Probiotics add more good bacteria to provide more biodiversity, so the digestive process can move along in a normal fashion, Dr. Bedford adds.

3. Reduce stress levels

Believe it or not, stress actually has a big affect on your gut health. A leaky gut may be the product of anxiety and stress.

To alleviate stress, try things like meditation, yoga, and deep abdominal breathing.

4. Stay active with exercise

If you’re experiencing unhealthy gut symptoms, you may want to consider revisiting your exercise routine. Adults should be getting the recommended 150 minutes to 300 minutes a week of moderate-intensity activity or 75 minutes to 150 minutes of vigorous-intensity physical activity.

“There are various studies in which people who exercise have been shown to have better gut health than those who don’t,” explains Dr. Bedford. “The circulation of blood and absorption from the gut that happens when you exercise is good for the gut, and good for all around health.”

Just be sure not to overdo it—too much exercise can actually add to your gut issues.

5. Get quality sleep

Poor sleep can negatively affect your gut microbiome, too. According to the Sleep Foundation, adults between the ages of 24 and 64 should be getting seven to nine hours of sleep a night. If you’re having trouble falling asleep at night or staying asleep, speak with your doctor to see if there’s anything you can do.

6. Treat underlying health issues

Treating underlying health issues is another important factor, as these conditions could have a big affect on your gut health, explains Dr. Bedford. Some of these include:

Diabetes

“This is certainly a big one,” says Dr. Bedford. “Any type of heart disease is important to treat, because it causes poor circulation to the gut. It can also affect the motility of the small intestine, slowing things down because the nerves aren’t working correctly due to the excess amount of sugar in the bloodstream.”

Obesity

“This could lead to heart disease, hypertension, and heart issues, which are all harmful to the gut as a whole,” says Dr. Bedford.

Irritable bowel syndrome, Ulcerative colitis, Crohn’s disease

“These all create inflammation in your digestive tracts and can cause bloating, cramping, and abdominal pain,” says Dr. Bedford.

If you think you may have an underlying condition, talk to your healthcare provider about testing for any of these issues and a treatment plan to treat the condition, and restore your digestive health.