What Is Gut Dysbiosis?

Gut dysbiosis is an imbalance of gut microorganisms—like bacteria, fungi, and protozoa—in your intestines. A balanced gut flora (microbiome) supports functions like digestion and immune response. People with gut dysbiosis typically have too little "good" bacteria or too much "bad" gut bacteria.

Frequent antibiotic use is the most common cause of gut dysbiosis. Gastrointestinal tract (GI) infections and diet are other contributors.  

Gas, abdominal pain, diarrhea, and constipation are common symptoms. Gut dysbiosis may also increase your risk of GI conditions like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). There's no clear way to treat gut dysbiosis, but fecal microbiota transplantation has shown promising results. Probiotics might also help. 

Types of Gut Dysbiosis

Everyone has a unique gut microbiome. It consists primarily of bacteria as well as some fungi and protozoa. Your gut naturally contains both harmful and beneficial bacteria, and they usually live in harmony. Three types of dysbiosis can cause gut flora imbalance: 

• Type 1: Your gut flora lacks healthy levels of beneficial bacteria. If you have this type of dysbiosis, you've lost too much "good" bacteria.
• Type 2: Harmful bacteria overgrow in your gut, causing too-high levels of harmful bacteria in your intestines.
• Type 3: You lose harmful and beneficial gut bacteria, significantly reducing your gut flora diversity—your gut's mix of different bacteria types.

Gut Dysbiosis Symptoms 

Imbalanced gut bacteria can change how your body digests. leading to gas buildup and discomfort. As a result, people with gut dysbiosis often experience GI symptoms like:

• Bloating
• Gas
• Nausea 
• Vomiting
• Diarrhea
• Constipation

Gut dysbiosis can damage your gut and cause inflammation. Over time, it may affect your gut permeability, allowing bacteria and toxins to leak through your intestinal lining. This can affect your immune system and reduce your ability to fight infections.

An imbalanced microbiome can also contribute to skin conditions like atopic dermatitis (the most common type of eczema), acne, dandruff, and psoriasis—an autoimmune condition that causes scaly, red, itchy patches on your skin.

What Causes Gut Dysbiosis? 

Gut dysbiosis occurs when the amount or type of gut microbes changes. It's often caused by a GI tract infection that increases harmful bacteria. The harmful bacteria overpowers good bacteria over time. 

Antibiotic use—especially often or for extended periods—is the most common cause of gut dysbiosis. Antibiotics treat bacterial infections by killing or reducing harmful bacteria, but they also reduce beneficial bacteria. They can also reduce the overall gut flora needed for a healthy gut. 

Other risk factors for gut dysbiosis include: 

• Genetics: Every person has a unique gut microbiome, but some people may be more susceptible to imbalances due to their existing flora. 
• Diet: Eating high-sugar, ultra-processed, and low-fiber diets can change gut flora. Fiber helps promote beneficial gut bacteria, while ultra-processed and high-sugar diets feed harmful bacteria—potentially leading to overgrowth.
• Smoking and alcohol: Smoking and frequent alcohol use can reduce beneficial gut flora.
• Age: Gut flora diversity often lowers with age, likely due to diet and medication changes.

How Is Gut Dysbiosis Diagnosed?  

There's no standard way to diagnose gut dysbiosis. Everyone has different gut microbiomes, so creating specific standards for diagnosis can be challenging. Still, your healthcare provider can order diagnostic tests to help identify levels of harmful or beneficial bacteria living in your gut. 

Diagnostic tests used to help diagnose gut dysbiosis include:  

• Comprehensive digestive stool analysis (CDSA): A stool sample is analyzed in a lab to identify different bacteria populations and potential infections.
• Intestinal biopsy: A sample of your gut tissue is removed and examined under a microscope to identify different types of gut flora and underlying GI diseases.
• Breath testing: Breath tests measure the amount of hydrogen and methane you produce. High levels indicate gut imbalance. These tests are often used to diagnose small bacterial intestinal overgrowth (SIBO), an overgrowth of bacteria in your small intestine.

Gut Dysbiosis Treatment

The main goal of gut dysbiosis treatment is to rebalance gut bacteria diversity. This is typically achieved by increasing beneficial microbes and decreasing harmful microbes with probiotics or fecal microbiota transplantation.

Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) places healthy donor feces into the colon of someone with gut dysbiosis. This helps replace "good" bacteria that may be low or missing due to factors like antibiotic use, IBS, or IBD. 

Restoring beneficial bacteria improves gut microbiota diversity and fights infections caused by high levels of harmful bacteria. Bacteria may also be inserted into the stomach through a tube down the mouth or by ingesting a freeze-dried donor stool capsule.

Probiotics

Probiotics are microorganisms that help decrease harmful bacteria and increase good bacteria. Studies show that probiotics can help replenish low levels of "good" bacteria in people with gut dysbiosis. They might be particularly effective in reducing gut dysbiosis caused by antibiotic use.

Much research focuses on probiotic supplements, which aren't regulated by the FDA. Always consult with a healthcare provider before trying a supplement to ensure it's safe for you to use. When possible, purchase probiotic supplements from companies that are certified by third-party organizations like U.S. Pharmacopeia and NSF International, which set strict standards for supplement quality and safety.

Probiotic-rich fermented foods also offer many gut health benefits. Research suggests that they're generally more effective than probiotic supplements at supporting gut health. They contain important nutrients and are processed more effectively by the body.

Probiotic-rich fermented foods include:

• Kefir
• Yogurt
• Kimchi
• Kombucha
• Sauerkraut
• Tempeh
  

Medication

People with gut dysbiosis and IBS may be given an antibiotic called Xifazan (rifaximin). This medication helps relieve symptoms of IBS and treats infections caused by harmful bacterial overgrowth. 

How To Prevent Gut Dysbiosis

Gut-friendly lifestyle changes may be the best way to keep your gut microbiome balanced and happy. Research-backed ways to help prevent gut dysbiosis and improve gut health include diet, mindful antibiotic use, and regular exercise.

Diet and Antibiotic Use

Recommendations around diet and antibiotic use include the following:

• Eat more fiber: High-fiber foods like fruits, vegetables, and whole grains can help preserve bacterial gut diversity. Introduce more fiber slowly to avoid potential GI symptoms like bas and diarrhea, and drink plenty of water.
• Limit ultra-processed foods and foods high in added sugar: These types of foods decrease beneficial bacteria and increase harmful bacteria.
• Consume probiotics and prebiotics with antibiotics: Including foods rich in probiotics and prebiotics during and after antibiotic treatment can help preserve more good gut bacteria. Research shows mixed results on the effectiveness of supplements.
• Avoid chronic antibiotic use: If possible, be mindful of long-term or frequent antibiotic use, which can lead to the overgrowth of harmful microorganisms. Talk to your healthcare provider about other treatment options that might be possible based on your diagnosis.

Other Tips

Gut-supportive lifestyle tips include the following:

• Avoid smoking and heavy drinking: These habits can alter gut bacteria and increase gut permeability. People with chronic alcohol use often have more harmful bacteria compared to those who don't drink heavily.
• Practice oral hygiene: Oral health, including oral bacteria, might affect gut health. More research is needed in this area.
• Exercise regularly: Moving your body for at least 150 minutes a week can help you maintain a healthy gut.

Related Conditions 

Imbalanced gut bacteria can affect your immune system in addition to your gut health. As a result, dysbiosis may cause intestinal inflammation and damage—leading to GI conditions like:

• Leaky gut syndrome: An impaired intestinal barrier that allows bacteria and toxins into your bloodstream.
• Inflammatory bowel disease (IBD): People with Crohn's disease and ulcerative colitis often have lower gut bacteria diversity and higher inflammatory bacteria like E. Coli in their intestines.
• Irritable bowel syndrome (IBS): Gut dysbiosis might contribute to inflammation, leaky gut, and stress that triggers this chronic GI condition.

Inflammation caused by gut dysbiosis may also affect other body systems, like your skin and joints. It may increase your risk of developing inflammatory conditions like:

• Type 2 diabetes: An imbalanced gut microbiome has been linked to type 2 diabetes. Diabetes medications like metformin also appear to alter gut bacteria. 
• Eczema: People with this inflammatory skin condition often have gut and skin dysbiosis that changes how their microbiomes and immune responses function. 
• Rheumatoid arthritis: Stool samples of people with this chronic inflammatory joint disorder show signs of gut dysbiosis and leaky gut.
• Ankylosing spondylitis: Gut dysbiosis has been linked to genetic factors, gut inflammation, and immune responses found in people with ankylosing spondylitis—an inflammatory condition that affects spinal joints and ligaments.  
• Obesity: Adults and children with obesity may have higher or lower levels of specific gut bacteria compared to those without obesity. Dysbiosis may also contribute to obesity, so the link isn't fully understood. Weight is affected by various biological, environmental, and social factors.

A Quick Review

Gut dysbiosis is an imbalance of gut microorganisms in your intestines—too few beneficial bacteria, too many harmful bacteria, or overall lower gut flora diversity. The condition isn't fully understood, and researchers are still trying to identify effective diagnosis, treatment, and prevention methods.

GI infections, antibiotic use, and diet are a few common causes of gut dysbiosis. You may experience GI symptoms like cramping and bloating, and you may be more at risk of developing inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).

Probiotic therapy and fecal microbiota transplantation may help treat some cases of gut dysbiosis. However, maintaining a healthy gut with diet, lifestyle, and careful antibiotic use is likely the best way to maintain gut health.