How do you know if your gut is less than healthy? There are a number of common signs that may indicate an imbalance in your microbiome.

Gas, Bloating and Other Stomach Issues

“Symptoms of food intolerance such as poor digestion, bloating and stomach pain may stem from problems with bacteria in the gut,” says Davis.

Now, it’s important to understand that food intolerances are not the same as food allergies. With a food allergy, you experience an immune reaction to something you eat; this could cause shortness of breath, hives, swelling in your mouth or tongue or itchiness, and it’s not only uncomfortable, but can be life threatening. Food intolerances, on the other hand, affect up to 20% of the population and specifically lead to those aforementioned stomach issues, which are unpleasant and can be serious, but aren’t dangerous in the same way an allergy would be. Some individuals might even be able to handle small amounts of a food of which they’re intolerant without too much discomfort.

When you experience side effects like gas and bloating after eating certain foods, this may be an indication that the bacteria in your gut isn’t breaking down those foods the way it should.

(Note: Product details and pricing are accurate as of the publication date and are subject to change.)

Unintentional Weight Fluctuations

It’s not exactly a stretch to see how your gut health might impact your weight; after all, when your gut is balanced, it easily processes your food and eliminates waste in a regular manner. You can eat your typical diet, and your weight most likely only fluctuates when there is a direct change in eating habits or physical activity.

But there’s more to the connection between gut health and weight. Some gut bacteria actually have an impact on how many calories you can extract from your food, and microbial richness has been shown in some studies to be linked to adult BMI and metabolism. In other words, the gut microbiome can play a role in weight gain and weight loss. So, if you’re eating normally but seem to be slowly gaining—or losing—weight, poor gut health and lack of diversity in your microbiome may be to blame.

One important caveat is that unintentional weight loss or weight gain can also be a sign of other serious health conditions, like cancer, so if you’re experiencing either one, you should speak with your doctor as soon as possible.

Skin Issues

You may have noticed that your skin tends to break out when you eat certain foods, like those high in refined sugar or saturated fat, and that may be due to the bacteria in your gut. According to one 2021 study, those kinds of foods promote an imbalance of gut bacteria that can contribute to a variety of skin issues, including acne, rosacea, eczema, psoriasis and dandruff.

In fact, the connection between our gut and our skin is more evident when we look at the microbiome of individuals who do and who do not have these types of inflammatory skin conditions. That same study found that individuals living with rosacea, for example, are also likely to experience gastrointestinal issues, and while only 2% to 3% of the general population have psoriasis, that range jumps to 7% to 11% among people with irritable bowel disease.

Moodiness, Irritability and Trouble With Concentration

“When I talk to my patients about the connection between mental health and gut health, I usually tell them that our feelings and emotions are strongly associated with the GI tract,” says Dr. Seeley.

“For example, when our brain is in overdrive from anxiety or depression, the nerves that stimulate the brain are constantly firing. The same thing happens in the GI tract,” she says. “There are nerves that stimulate the gut that also start firing, so now this cycle has been created. The psychological symptoms worsen the GI symptoms, and the GI symptoms worsen the psychological symptoms. This can continue until the cycle is broken through medications, lifestyle and/or dietary modifications.”

Even though the precise link between the gut and brain is not entirely clear, studies show considerable evidence of the effect of gut health on our mental state. After all, over half of patients with irritable bowel disorder also have depression, anxiety or sleep problems, and it’s not uncommon for depression and generalized anxiety disorder to be associated with gastrointestinal issues.

While research on this connection may be ongoing, it’s clear that the gastrointestinal tract and brain communicate; in fact, evidence-based clinical practice guidelines for irritable bowel syndrome from the Journal of Gastroenterology specifically include psychotherapy and psychopharmacological treatments.

Fatigue or Insomnia

Struggling to sleep, or sleeping too much? This is another area where your gut health may be affecting your life.

“The gut produces much of the body’s serotonin, which affects mood and sleep,” explains Davis. “Functions of the gut, and its activity, interact with our sleep/eating rhythms and emotions.”

And, as we saw with the connection between the gut and mental health, the link between sleep and gut health is a two-way street. “Sleep is important in achieving a healthy gut,” says Dr. Seeley. “Getting a good amount of sleep each night helps maintain a healthy gut microbiome. Lack of sleep can lead to digestive problems, and these problems may feed into a vicious cycle.”

Sugar Cravings

Microbes: They’re just like us! Or at least they are in that different microbes prefer different types of foods. Some love carbohydrates, others grow best on dietary fiber or certain fats, and yeast, in particular, feeds on sugar. Because of this, there is a line of thought that the more you indulge in those cravings, the more the microorganisms influencing those cravings grow. This perpetuates the cycle, leading to an imbalance in your gut with the sugar-loving, pro-inflammatory bacteria taking over, which may lead to other health issues as well.