Your microbiome may be trying to get your attention.

Have you listened to your gut lately? It could be trying to tell you something. Mounting evidence shows that tiny microorganisms inside the gut play a huge role not just in digestion, but in our overall health.

Welcome to your microbiome, a bustling, microscopic universe that begins forming at birth and can grow to up to 5 pounds. Teeming with trillions of organisms, each person's microbiome is different, with its own unique mix of fungi, bacteria, and viruses.

While most of these bacteria are good and even essential for our health, some can be harmful. As long as the mix stays in a healthy balance, with plenty of good guys to fight off the bad ones, your digestion and many other daily body functions keep humming right along.

A poor diet, along with other things, can knock that mix out of balance. Over time, a gut imbalance can throw your whole body out of whack — sometimes with serious consequences.

"An unhealthy gut microbiome has been linked to a number of diseases, including colon cancer, obesity, and many diseases outside the GI tract," says Alyssa Parian, MD, assistant professor at Johns Hopkins Medicine and a spokesperson for the American Gastroenterological Association.

How's your microbiome doing these days? Here are six clues that it may need a tune-up:

1. Your Stomach is Often Upset

It's pretty much a no-brainer: An unhappy gut will likely cause stomach problems. Gas, bloating, heartburn, and diarrhea or constipation are all common symptoms. (Of course, other things may be the cause, too — everything from that burrito you had for lunch to an underlying condition like Crohn's — so see a doctor if symptoms keep up.)

2. Your Skin is Breaking Out

If you're experiencing skin flare-ups, the problem may be your gut. Studies have linked inflammation and other issues in the gut with a number of skin conditions, including acne, eczema, psoriasis, and rosacea.

3. You're Gaining or Losing Weight

Dropping or adding pounds without trying is often a big warning sign of a gut imbalance. "Metabolism has been strongly linked to the gut microbiome," says Parian. If your gut isn't working right, your body can't properly absorb nutrients, control blood sugar, or store fat. You may lose weight because of too much bacteria in your small intestine, or overeat to try to make up for lost nutrients.

4. You Crave More (and More) Sugar

It's a vicious cycle: The more sugar you eat or drink, the more you crave — and the more it messes with your gut. "Too much added sugars can disrupt the balance of microbes," says Frances Largeman-Roth, RDN, author of Prevention Healing Kitchen: Smoothies and Juices — 100+ Delicious Recipes for Optimal Wellness. "You're feeding it the wrong things, and not providing the right fuel for the good bacteria."

5. You Have Bad Breath

Maybe it was the garlic pasta you had for dinner, or you're not always brushing your teeth like you should. But frequent bad breath can have other causes too, like chronic heartburn or GERD. If your breath is often stinky, your microbiome's bacteria could be to blame.

6. You Feel Anxious or Moody — a Lot

There's a reason we say our stomach is in knots when we're nervous, or why we may get a sudden diarrhea attack when we're feeling stressed out. "Anxiety makes gut issues worse," Largeman-Roth says. Early research suggests the opposite may also be true. Most of the body's seratonin, a hormone that regulates our emotions, is stored in the gut, firing off signals to the brain. It's no surprise, then, that a grouchy, off-kilter gut could make us feel grouchy or anxious, too.

Young girl with stomach pain on white background
Credit: Nednapa Chumjumpa / EyeEm/Getty Images

What to Do About an Unhealthy Gut

A messed-up microbiome may sound bad, but there's good news: Changing up your diet can improve your microbiome quickly — sometimes in a matter of days, says Parian. Get started with these four tips:

  1. Mix up your meals.The more diverse your diet, the better for your gut, Parian says. Focus on fresh fruits and veggies, whole grains, lean meat and fish. Add fermented foods like yogurt, kimchi, and sauerkraut — they have probiotics, or good bacteria that help keep your gut in check.
  2. Cut down on added sugars. "It's not like you can never have sweets, but try to limit them," Parian suggests.
  3. Shop the outer edges of the supermarket. It's where the freshest, most nutritious foods are. Spend less time browsing the inner aisles, and buy less packaged foods with preservatives, says Parian. "More and more studies show that preservatives can cause problems," she adds.
  4. Fill up on fiber. "Most Americans don't get nearly enough fiber, and our gut health is suffering because of it," says Largeman-Roth. Go for whole grains, nuts, seeds, and fresh fruits and vegetables. But take it slow — too much fiber at once can backfire.

When to Get Help

Gut symptoms can sometimes signal something more serious. "Not all GI illnesses can be treated with only a change in your diet," says Parian. See a doctor if your symptoms keep up for 10 days or longer. "If you are having unintentional weight loss or blood in your stool, you should see a doctor immediately," Parian says. You may have an underlying condition that needs treatment.