Dysbiosis is a term used to describe an imbalance or disruption of the microorganisms that typically inhabit the gut (collectively known as the gut microbiome or gut microbiota). While it can mean there are too many harmful microbes, dysbiosis can involve changes in the types, amounts, and diversity of microorganisms in the gut.
While we're still learning about how the gut microbiome impacts human health, it plays key roles in digestion and immunity. This article will explain what dysbiosis is, its causes, possible symptoms, and strategies for keeping your gut microbiome healthy.
What Is Dysbiosis?
Dysbiosis describes an imbalance or disruption in the gut microbiome, such as changes in:
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Diversity (how many different types of microbes there are)
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Abundance (how many microbes of a single species there are)
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Activity (what the microbes do)
While dysbiosis has been linked to a number of different chronic conditions, including obesity, depression, anxiety, insulin resistance, type 2 diabetes, and colorectal cancer, we're still learning whether changes in the gut microbiome are causes of these conditions, result from them, or a combination of both.
What Does a Healthy Gut Microbiome Look Like?
Each person's gut microbiome is like a fingerprint, unique to the individual. While there isn't one universally accepted definition of what an "ideal" microbiome looks like, it's important that the gut contains a diverse community of different microorganisms.
Why is a diverse microbiome so important? Just like how humans have different jobs, so do the microorganisms living in your gut. Here are some of the most important roles your gut microbiome plays:
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Fermenting certain dietary components, such as certain types of dietary fiber
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Producing beneficial compounds, such as short-chain fatty acids (SCFAs)
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Supporting the normal function of the gut barrier
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Interacting with the immune system
Having a diverse microbial community ensures all these different roles are fulfilled.
What Happens When the Gut Microbiome Becomes Imbalanced?
Dysbiosis can be used to describe several different types of changes:
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Changes in microbial diversity: Some people may experience reductions in gut bacteria and other microorganisms.
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Overgrowth or reduction of certain microorganisms: In some cases, harmful microorganisms may outnumber good bacteria or healthy bacteria
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Changes in microbial activity: Certain microbes may become less active, reducing the production of beneficial compounds such as SCFAs.
While "imbalanced gut bacteria" is often used to describe intestinal dysbiosis, in practice, dysbiosis is far more nuanced than simply having too many bad bacteria; it may also reflect disruptions in good or "friendly" bacteria or shifts in the activity of normally harmless bacteria.
What Causes Dysbiosis?
Many diet, environmental, and lifestyle factors can contribute to disruptions in the diversity, abundance, or activity of the gut microbiome, including:
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Diet: The foods you eat help shape which microorganisms thrive; dietary patterns, food variety, and fiber intake can all influence the function and composition of the microbiome.
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Antibiotic use: Antibiotics may reduce or alter both harmful bacteria and beneficial bacteria, and these changes may persist after treatment ends.
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Certain medications: Other medications, such as proton pump inhibitors, have also been linked with changes in gut microbiome composition.
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Illness or infection: Gastrointestinal illnesses can temporarily or more persistently alter the gut microbiome.
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Chronic stress: Ongoing stress may alter the gut microbiome via the gut-brain axis, including changes in immunity, gut motility, and the intestinal environment.
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Changes in sleep: Poor sleep has been linked to shifts in the gut microbiome, although the relationship is still being studied.
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Lifestyle factors: Physical activity, heavy intake of alcoholic beverages, smoking, and travel may influence the gut microbiome to varying degrees.
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Underlying gastrointestinal conditions: Conditions such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have been linked to differences in the gut microbiome, although it's still unclear whether these changes contribute to the conditions, result from them, or both.
Rather than being caused by a single factor, dysbiosis likely reflects a complex interplay among diet, medications, health conditions, lifestyle, and environmental factors, and what constitutes "dysbiosis" can vary significantly from person to person.
Antibiotics and Dysbiosis
Antibiotics can alter the community of microorganisms living in your gut because many antibiotics kill a wide range of bacteria — not just the pathogenic microorganisms causing the infection. As a result, the total number of bacteria and bacterial diversity may decrease after antibiotic treatment. Additionally, there may be changes in the metabolites (by-products of metabolism) produced by your gut microbiome after taking antibiotics. For example, there may be a reduction in beneficial SCFAs following antibiotic treatment.
While it can be helpful to discuss alternatives to antibiotic treatment with your doctor, antibiotics may be medically necessary in some cases, such as persistent urinary tract infections. If you do need to take antibiotics, it's important to take them as directed.
What Are the Symptoms of Dysbiosis?
There are many potential symptoms of dysbiosis, but in most cases, they can also occur with other digestive conditions. Still, some of the most common symptoms of dysbiosis include:
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Gas
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Abdominal discomfort
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Changes in bowel movement frequency
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Diarrhea
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Constipation
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Fatigue
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Brain fog
However, while dysbiosis has been linked with digestive symptoms, these symptoms alone cannot establish whether a person has dysbiosis. Persistent digestive symptoms should be discussed with your healthcare provider, as they can be caused by other gut conditions, including IBS, IBD, or celiac disease.
Can Dysbiosis Cause Bloating and Gas?
Yes, dysbiosis can cause bloating and gas, most likely due to changes in microbial fermentation patterns. Increased fermentation of certain food components, such as FODMAPs, can contribute to gas, bloating, abdominal discomfort, and other digestive symptoms.
How Is Dysbiosis Diagnosed
There is no universally accepted test that can definitively diagnose gut dysbiosis in every person. Instead, your healthcare provider may consider:
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Your symptoms and medical history
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Other underlying conditions
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Diet and medication history
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Relevant clinical testing when appropriate
Many people use commercially available microbiome tests to get information about their gut microbiome. Although a stool microbiome test can provide information about your individual stool microbial composition, the lack of a standardized "ideal" microbiome makes it difficult to determine whether a person's microbiome is "balanced" or "imbalanced."
A hydrogen breath test may be used to identify overgrowth of bacteria and methanogens (another type of microorganism) in the small intestine. However, these tests also have limitations, and it's important that your provider has experience interpreting the results.
At the end of the day, treatment should focus on addressing your individual symptoms and underlying conditions, not on trying to achieve the "perfect" microbiome. The reality is that a healthy microbiome can look different for everyone, so what is "healthy" for one person may not be healthy for another.
How to Support a Healthy Gut Microbiome
Even though we don't yet have a clear definition of what a "normal" microbiome looks like, there are several things you can do to support a healthy gut microbiome. However, keep in mind that while these strategies may support a healthy microbiome, they may not "cure" dysbiosis.
Eat a Diverse Diet
Diet is one of the most easily adjusted factors contributing to microbiome diversity. Since different microbes feed on different food components, having a wide variety of different plant-based foods in your diet may support a healthy, diverse gut microbiome.
Include Fiber-Rich Foods
High-fiber foods like fruits, vegetables, whole grains, legumes, nuts, and seeds can all support your gut microbes. If certain foods trigger your digestive symptoms (such as high FODMAP foods), you may need to modify this approach based on your individual tolerance.
If you don't currently eat many high-fiber foods, it's important to increase your intake gradually to reduce the likelihood of excessive gas and bloating. Additionally, if you're experiencing significant gastrointestinal symptoms such as persistent diarrhea, bloating, or abdominal pain, it's best to check with your healthcare provider before adding large amounts of fiber to your diet, as too much fiber can worsen symptoms in some cases.
Be Thoughtful About Antibiotics and Medications
While it's always important to take medications as prescribed, it's also important to only use antibiotics when medically appropriate and as directed by your healthcare provider. This includes taking the entire course of antibiotics, even if you feel better. Stopping antibiotics before they run out has been linked to increased antibiotic resistance, so it's important to take the full course.
In some cases, taking specific probiotics during antibiotic treatment may help restore healthy bacteria and prevent antibiotic-associated diarrhea, but this should be discussed with your healthcare provider in advance.
Prioritize Sleep, Movement, and Stress Management
Lifestyle factors such as sleep, physical activity, and stress can all influence our microbiome and digestive health. Having a regular sleep routine, engaging in physical activity you enjoy, and managing stress levels are all good ways to support not only your microbiome but also your overall well-being.
Dysbiosis and the Low FODMAP Diet
If you have IBS, you may have heard of the low FODMAP diet as a way to manage IBS symptoms. FODMAPs are fermentable carbohydrates that can cause symptoms like gas and bloating, and are some of the most common foods that can cause IBS symptoms.
However, it's important to note that having food intolerances or being sensitive to certain FODMAPs does not necessarily indicate dysbiosis. While both can cause similar symptoms and are related to gut microbiology and digestion, they are two separate conditions.
Following a low FODMAP diet can reduce digestive symptoms for some people with IBS. It consists of three phases: elimination, reintroduction, and personalization or maintenance. The purpose of the elimination phase is to get your symptoms under control, while the reintroduction phase involves doing a series of "food challenges" to determine which (if any) FODMAP groups you're intolerant to. Finally, the personalization phase is where you eat a diet that includes the FODMAPs you can tolerate.
Long-term dietary restriction is not the goal of the low FODMAP diet. Instead, it's to eat as varied a diet as possible while managing your symptoms. Since many FODMAPs are prebiotics (food for your good gut microbes), restricting them long-term could be detrimental to your gut microbiome and overall gut health.
How to Support Your Gut Without Unnecessary Restriction
So, what can you do if you know certain FODMAPs trigger symptoms but want to eat a varied diet to feed your gut microbiome? That's where digestive enzymes that break down specific FODMAPs come in. Digestive enzymes break down certain FODMAPs, reducing fermentation in the gut and helping relieve common FODMAP-related digestive symptoms like gas, bloating, and abdominal discomfort.
FODZYME breaks down FODMAPs — fructan, GOS, lactose — into more digestible carbohydrates. While it's not a treatment for dysbiosis, FODZYME relieves gas, bloating, and digestive discomfort caused by FODMAP exposure.
Remember, dysbiosis, or a disruption of the gut microbiome, can have many contributing factors, and digestive symptoms alone don't necessarily indicate dysbiosis. However, if you experience FODMAP-related digestive symptoms, a digestive enzyme supplement like FODZYME may help.