Trust your gut. This tried-and-true advice is often given when we’re facing a tough decision.
But we now know that “trusting our gut” is also key to how we feel each day—and to our long-term health.
Our gut, officially known as the gastrointestinal (GI) tract, is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. These hollow organs include the mouth, esophagus, stomach, small intestine, large intestine and anus. 
Our gut is responsible for the digestive functions that keep us alive. Our gut carries food from our mouths to our stomachs; it converts our food into absorbable nutrients and stored energy; and it moves waste out of our bodies. 
However, scientists have recently discovered that the gut is like a second brain. This second brain rules not only our digestion, but it impacts our moods, how we think and our overall health. 
It has been linked to our immune system and to our inflammation levels. It has also been linked to chronic conditions including asthma and allergies, heart disease, multiple sclerosis, obesity, some cancers and type 2 diabetes. Gut health has even been linked to anxiety and depression, schizophrenia and dementia. 
This link is due to the trillions of bacteria that live in our gut, known as our microbiome.
Gut bacteria generally won’t make us sick. In fact, most gut bacteria are helpful to our health. They keep pathogens (harmful microorganisms) in check and contribute to immune function. 
While research on gut bacteria is new, studies have found that certain environments, foods and behaviors can influence our gut health. 
Think of it this way. Habits like a poor diet, smoking, drinking, lack of exercise and high stress levels can damage our hearts, lungs and brains. These same habits can also hurt our gut.
When your gut bacteria is thrown out of balance for any reason, it’s often easy to tell. Bloating, gas, diarrhea, stomach pain or nausea are the initial, often manageable symptoms that your gut may be out of balance.
Here are 3 ways to use nutrition to protect and support your gut:
1. Try fermented foods
Probiotics (pro meaning “for” and biota meaning “life") are the beneficial bacteria found in fermented foods including yogurt, sauerkraut and kimchi.
Research has found that it’s possible to treat and prevent certain types of conditions by consuming this live bacteria.
These conditions include:
- Source: Harvard Medical School
Depending on your current state of health, be sure to talk to your doctor before starting a probiotic supplement or incorporating foods high in probiotics into your diet.
2. Get more fiber
Limiting foods low in fiber such as processed meats, and refined sugars can improve your gut health. As can increasing your daily intake of fiber.  Based on your personalized food list, add more fruits, vegetables, whole grains, nuts and seeds to your diet.
Keep in mind that as you add more fiber to your diet you may feel bloated or constipated. This is not necessarily a sign that your gut is in trouble. However, be sure to gradually add these high fiber foods into your diet, make sure you are drinking water, and track how your body reacts.
3. Eat a gut-balancing diet
Compare this list of gut healthy staples against your personalized food list and incorporate the ones that are the best matches for you:
Whole grains: Compared to refined carbohydrates like white bread and pasta, whole grains provide fiber. When gut bacteria ferments fiber, it encourages proper function in the cells lining the colon, where 70 percent of our immune cells live.
Leafy greens: Spinach and kale are excellent sources of fiber, folate, vitamin C, vitamin K and vitamin A. Research shows that leafy greens also contain a specific type of sugar that helps fuel growth of healthy gut bacteria.
Lean protein: People with IBS or bowel sensitivity should opt for lean proteins, such as salmon and the white meat from chicken. It’s also important to avoid foods that are rich in fat, including fried foods. These high-fat foods can trigger colon contractions. In addition, red meat can promote the growth of a colon bacteria that increases the risk of clogged arteries.
Fruits low in sugar: Choose berries and citrus fruits, such as oranges and grapefruit, instead of apples and pears. Bananas are also low in sugar, fiber-rich and contain a substance that stimulates the growth of good gut bacteria.
Avocados: A superfood, avocados are packed with fiber and essential nutrients including potassium, which helps promote healthy digestive function. However, while avocados are high in nutrients they’re also high in fat, so be sure to eat them in moderation.
- Source: John Hopkins Medicine
The bacteria that lives in your gut eats leftovers—what’s left in your colon after your cells have digested all of the nutrients. 
It’s important you feed them the foods that fuel your body. Your genes can help you determine which foods, out of all the major food groups, are the best fit for your body.
Learn how our personalized nutrition science can support your health.
 National Institute of Diabetes and Digestive and Kidney Diseases, Your Digestive System & How It Works
 Time Magazine, Here's Everything You Need to Know About Gut Health
 Johns Hopkins Medicine, The Brain-Gut Connection
 Harvard Medical School, Health Benefits of Taking Probiotics
 Johns Hopkins Medicine, 5 Foods To Improve Your Digestion