Intestinal Permeability (“Leaky Gut”) & GI Function – Featuring the GI MAP Test

Our gut bacteria and the other microorganisms living in our gastrointestinal (GI) tract play a vital role in our overall health and well-being, affecting our digestion, emotions, cognition, immunity, metabolism, skin, and more. After all, since the human body contains more bacterial cells than human cells, it makes sense that these microorganisms could affect every organ and body system! This is why our gut health is so important, and why those of us practicing naturopathic functional medicine stand by Hippocrates’ belief that “all disease begins in the gut”. 

The microorganisms that make up our gut microbiota are protective — even beneficial — when there’s a healthy balance of “good” and “bad” microbes in the GI tract. However, in a dysbiotic gut microbiota — meaning there’s an imbalance of “good” and “bad” microbes in the gut — our overall health and well-being can suffer. Gut dysbiosis can trigger the development or worsening of various diseases such as autoimmune disorders, cardiometabolic conditions, and leaky gut.

In this blog post, we’ll discuss what leaky gut is, how to test for it, and how you can measure your intestinal health using one of my preferred tests: the GI-MAP.  

What is leaky gut?

Otherwise known as leaky gut syndrome or intestinal permeability, leaky gut is a term used to describe an impaired intestinal lining. This means the intestinal barrier is compromised, allowing toxins, antigens, and bacteria from the gut to pass through the intestinal lining and enter the bloodstream. 

When this happens, it can lead to the development of chronic diseases and undesirable GI symptoms such as diarrhea, bloating, and gas. Other leaky gut symptoms may include skin irritation, food sensitivities, fatigue, joint pain, depression, and anxiety. Having an autoimmune disease is another symptom of leaky gut, as intestinal permeability is often at the root of chronic diseases! 

Gut testing 101

Whether you’re experiencing gut issues like SIBO or IBS; other symptoms like chronic fatigue, brain fog, joint pain, anxiety, skin rashes, acne, allergies, or autoimmunity; or you’re generally feeling unwell, your gut microbiota is an excellent place to look for clues about your health. My preferred gut health test is the GI-MAP™, a comprehensive stool test that uses quantitative polymerase chain reaction (qPCR) technology to measure microorganisms in the gut and detect conditions like leaky gut, dysbiosis, GI inflammation, and more. 

Gut microbiota testing can help us determine whether the microbes in your GI tract are responsible for the symptoms or conditions you’re experiencing, and guide us in creating the right treatment plan for you. It can also be used to recommend additional testing and therapeutic approaches — and monitor your progress after treatment begins.  

What gut microbiota testing can detect

So what does the GI-MAP look for, exactly? Lots of things! 

Using a single stool sample, the test measures the type and amount of various microorganisms in the gut. An imbalance of “good” and “bad” microorganisms in the gut microbiota can indicate dysbiosis and certain markers of intestinal health can point to leaky gut syndrome.  

Specifically, the GI-MAP measures the following bacteria, parasites, fungi, and viruses in the gut:

• Bacterial pathogens like Campylobacter, Clostridium difficile (C. difficile), Enterohemorrhagic E. coli (EHEC), E. coli O157, Enteroinvasive E. coli/Shigella, Shiga-like Toxin E. coli stx1, Enterotoxigenic E. coli LT/ST, Shiga-like Toxin E. coli stx2, Salmonella, Vibrio cholerae, and Yersinia enterocolitica.
• Parasitic pathogens like Giardia, Cryptosporidium, and Entamoeba histolytica.
• Viral pathogens such as Adenovirus 40/41 and Norovirus GI/GII.
• Helicobacter pylori (H. pylori) and H. pylori virulence factors (e.g. BabA, CagA, DupA, IceA, OipA, VacA, VirB, and VirD).
• Commensal (symbiotic) bacteria like Bacteroides fragilis, Bifidobacterium spp., Enterococcus spp., Escherichia spp., Lactobacillus spp., Enterobacter spp., Faecalibacterium prausnitzii, and Roseburia spp.
• Bacterial phlya such as Bacteroidetes and Firmicutes.
• Opportunistic bacteria:
  • Dysbiotic bacteria: Bacillus spp., Enterococcus faecalis, Enterococcus faecium, Morganella spp., Pseudomonas spp., Pseudomonas aeroginosa, Staphylococcus spp., Staphylococcus aureus, and Streptococcus spp.

• Commensal bacteria: Desulfovibrio spp and Methanobacteriaceae.
• Inflammatory and autoimmune-related bacteria: Citrobacter spp., Citrobacter freundii, Klebsiella spp., Klebsiella pneumoniae, Mycobacterium avium subsp. Paratuberculosis, Proteus spp., and Proteus mirabilis.
• Commensal inflammatory and autoimmune-related bacteria: Enterobacter spp., Escherichia spp., Fusobacterium spp., and Prevotella spp.
• Fungi and yeast such as Candida albicans, Candida spp., Geotrichum spp., Microsporidia spp., and Rhodotorula spp.
• Viruses like Epstein-Barr (EBV) and Cytomegalovirus (CMV).
• Parasites:
  • Protozoa: Blastocystis hominis, Chilomastix mesnili, Cyclospora spp., Dientamoeba fragilis, Entameoba coli, Endolimax nana, and Pentatrichomonas hominis.

• Worms: Ancylostoma duodenale, Necatur americanus, Ascaris lumbricoides, Ascaris lumbricoides, and Trichuris trichiura.

In addition to measuring gut bacteria, parasites, fungi, and viruses, the GI-MAP looks at different intestinal health markers that can impact digestion, the immune response, gut inflammation, and antibiotic resistance specific to H. pylori infection (e.g. antibiotics that we may not respond to when treating H. pylori). Again, these results can clue us into whether dysbiosis may be present and indicate whether we could have leaky gut, GI inflammation, chronic infections, and food sensitivities. 

Other tests can be added to the GI-MAP if necessary, including zonulin (a biomarker for intestinal permeability). Zonulin are proteins that modulate the tight junctions of the intestinal lining, and elevated levels can point to increased intestinal permeability. 

Common patterns of gut dysbiosis

Without going too in-depth here, let’s look at a few common patterns of dysbiosis that may be seen with gut health testing. 

Firstly, insufficiency dysbiosis may occur if there are low to very low levels of commensal bacteria and bacterial phyla in the gut. Zonulin may also be elevated in this type of situation.

Secondly, inflammatory dysbiosis may occur when pathogens are present; patients have high levels of bacteria, yeast, and protozoa (including commensal and opportunistic bacteria), and intestinal health is impaired (e.g. leaky gut).

Digestive dysfunction dysbiosis can also occur when pathogens are present; certain intestinal health markers are abnormal; patients have high levels of bacterial phyla; and levels of bacteria, yeast, and protozoa are elevated.

The GI-MAP can tell us so much about our gut microbiota, intestinal health, and overall health and well-being!