Gut Health 101: What You Need to Know

The gut microbiota is home to trillions of microorganisms such as bacteria, fungi, viruses, archaea, and protozoans. Some of these microbes are commensal, meaning they’re normal members of the gut microbiota. Bifidobacterium spp., Akkermansia muciniphila, and Lactobacillus spp. are just a few examples of these types of microbes. 

Many of these microbes, in addition to being normal members of the gut microbiota, are also beneficial to the body. These microorganisms play a role in supporting our health, extracting nutrients from the foods we eat, helping maintain gut barrier integrity, and protecting us from potential pathogens. These types of microbes are added to probiotic supplements and fermented foods to support digestion, immunity, and gut microbial balance. 

Not all microbes are commensal or beneficial, however. Others are harmful under certain conditions, especially when they overgrow in the body or colonize in places they shouldn’t. When this happens, dysbiosis occurs. 

Dysbiosis and intestinal health

Within a balanced gut microbiota (known as eubiosis or a eubiotic gut), it’s usually the case that our commensal, opportunistic, and pathogenic microorganisms can co-exist without issue. However, in the case of gut dysbiosis — an imbalanced or dysbiotic gut microbiota — there are often more disease-promoting microbes in the GI tract than beneficial or commensal ones. Dysbiosis can also occur when the gut microbiota lacks microbial diversity and richness, or when excessive amounts of microbes colonize in places they shouldn’t. 

Small intestinal bacterial overgrowth (SIBO) and small intestinal fungal overgrowth (SIFO) are two types of dysbiosis that can occur when excessive amounts of bacteria and/or fungi colonize the small intestine: a location that isn’t normally home to large amounts of microbes. We’ll discuss these two topics in a future post!

The consequences of gut dysbiosis

You can probably tell by now that having a diverse and balanced gut microbiota is essential for optimal health and wellness. An imbalance of microorganisms in the gut impacts our health in so many different ways, affecting everything from digestion and nutrient absorption to cognition and immunity. After all, research suggests that 70 to 80 percent of our immune cells reside in the GI tract, aligning with Hippocrates’ belief that “all disease begins in the gut”.  

To name a few examples of how gut health affects our overall health and well-being, gut dysbiosis is shown to:

• Impair digestion.
• Drive inflammation.
• Promote disease.
• Disrupt the gut-brain axis (GBA).
• Increase intestinal permeability, leading to all sorts of health concerns.

Dysbiosis is also a leading cause of leaky gut syndrome (increased intestinal permeability), occurring when exposures to opportunistic or pathogenic microorganisms disrupt the balance of microbes in the gut. Poor diet, weakened immunity, antibiotic use, food sensitivities, environmental toxin exposure, and intestinal inflammation can also contribute to leaky gut.

Opportunistic and pathogenic microorganisms

Opportunistic and pathogenic microorganisms don’t cause symptoms or illness in everyone. However, they’re much more likely to pose problems when there are low levels of health-promoting microbes in the gut, more harmful microbes in the GI tract than helpful ones, and the gut barrier is permeable (AKA leaky gut). 

If the gut lining becomes permeable (or leaky), substances, pathogens, and food particles can pass through the intestinal barrier. Once they do, these particles can enter the bloodstream, trigger inflammation, and play a role in causing illness or disease. 

Examples of opportunistic microbes that can induce dysbiosis and increase intestinal permeability include gut bacteria like Bacillus spp., Staphylococcus spp., and Streptococcus spp. Parasites such as Blastocystis hominis and pathogenic microorganisms like Campylobacter, Helicobacter pylori (H. pylori), and Clostridium difficile can do the same.

Candida spp., a type of fungi, also falls under the category of opportunistic microbes, causing illness if it overgrows in the gut or elsewhere in the body. While it’s normal — even beneficial — for small amounts of candida to reside in the gut, mouth, skin, and vagina, candida can promote illness if it colonizes in excessive amounts. As we mentioned earlier, SIFO is a type of dysbiosis that occurs when fungi overgrow in the small intestine. 

Diagnosing leaky gut and dysbiosis

To achieve optimal gut health and correctly address symptoms like bloating, diarrhea, and abdominal pain, we need to know exactly what we’re up against before developing a treatment plan. The right treatment for leaky gut and dysbiosis varies widely depending on the specific situation. 

While taking a probiotic supplement and eating a variety of gut-friendly foods can certainly help promote intestinal balance and improve digestion, this isn’t always enough to move the needle. For many patients, it’s also necessary to address chronic infections (such as tick-borne illnesses), eradicate pathogens, treat fungal overgrowth, and repair the intestinal lining. 

This is where functional medicine testing comes in: advanced diagnostic tests that assess intestinal health and identify the root of the problem. Unlike most conventional tests used to assess intestinal health, functional testing looks at the health and functioning of the gut microbiota as a whole. 

These specialized tests can detect things like:

• The type and amount of microbes in stool, including commensal, opportunistic, and dysbiotic microbes.
• The presence of pathogens and parasites in stool.
• Digestive dysfunction and gut permeability.

Gut microbial balance, richness, and diversity are super important for overall health and well-being, but so too is having a strong gut barrier. Fortunately, it’s possible to address both gut dysbiosis and increased intestinal permeability with functional medicine testing; dietary and lifestyle modifications; and integrative therapies tailored to your specific needs. 

Ready to achieve optimal gut health? Book a free 15-minute consultation or schedule a full-length functional medicine visit today. 

References:

• https://www.diagnosticsolutionslab.com/assets/documents/gi-map-interpretive-guide.pdf 
• https://www.diagnosticsolutionslab.com/assets/documents/gi-map-white-paper.pdf 
• https://my.clevelandclinic.org/health/diseases/dysbiosis 
• https://link.springer.com/article/10.1007/s11739-023-03374-w 
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8001875/
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6996528/