In the conventional medical paradigm, practitioners are taught that most symptoms develop due to abnormal factors that are specific to the symptoms themselves. That your joint pain, for example, developed due to factors specific to your joints. Or that your depression developed due to factors specific to your brain. Or that your hypertension developed due to factors specific to your heart and vascular system.
It’s certainly a convenient explanation for why symptoms develop, and it fits perfectly with the philosophy that the body should be compartmentalized, and all tissues and organs and systems are separate and should be treated as such—take painkillers for your joint pain, antidepressants for your depression, and antihypertensive medication for your hypertension—but such a reductionistic perspective is deeply flawed.
The body, it turns out, is infinitely more complex and interconnected than most practitioners recognize, and symptoms don’t necessarily, and in fact almost never, develop due to factors specific to the symptoms themselves. More often, symptoms are the downstream effects of upstream causes, and those causes can be far removed.
However disconnected it might seem, your joint pain could actually be due to your mercury amalgam fillings, and not that you’re getting up there in age and your joints are losing cartilage, as your orthopedist suggested. Your depression could be due to a tick-borne infection, and not some neurotransmitter imbalance that your psychiatrist tried to convince you of. Your hypertension could be due to a magnesium deficiency, and not the genetic predisposition that your cardiologist speculated because of the other people in your family with hypertension.
Your symptoms, in other words, could be due to factors that are difficult, if not impossible, to identify unless you test for those factors, which is why I’m an advocate for using advanced biomarker tests to get as much data as you can about your health.
One such test that I recommend to people with unexplained chronic symptoms is a quantitative polymerase chain reaction (qPCR) stool analysis, given the extraordinary amount of information that the test provides. While there’s probably no end to the number of things that you’d rather do than collect a stool sample, the short-term cost of getting through the process and sending your sample to the lab for analysis is ultimately worth it for the long-term benefit of learning more about your health from this test than any other test that you’ve ever done.
To make this cost-benefit calculation easier, let’s explore six things that you can learn about your health from a qPCR stool analysis, so that the upside potential becomes obvious.
Parasites
Parasites are organisms that live in or on another organism, and that feed, grow, or multiply in a way that harms the host. The qPCR stool analysis tests for two kinds of parasites in the gastrointestinal tract: helminths and protozoa.
Helminths, such as Ancyclostroma duodenale, Ascaris lumbricoides, and Necator americanis, are parasitic worms that are visible to the naked eye in their adult stage. These parasites are typically acquired through consumption of contaminated food and water, and tend to only inhabit the gastrointestinal tract.
Protozoa, such as Blastocystis hominis, Giardia lamblia, and Dientamoeba fragilis, are single-celled parasitic organisms that require a microscope to see. They typically spread via contaminated food and water, contact with infected animals, contact with infected humans, or the bite of a vector, and tend to inhabit the gastrointestinal tract, but can also exist in tissues or blood.
Both helminths and protozoa cause digestive symptoms, such as diarrhea, constipation, and bloating, but can also cause other symptoms that aren’t easily attributed to the gastrointestinal tract, such as fatigue, joint pain, and headaches, making parasites an important focus whether you have digestive symptoms or not.
Bacteria
Bacteria are single-celled microorganisms that, depending on the species and the conditions of the host environment, can either benefit or harm the host. The qPCR stool analysis tests for three kinds of bacteria in the gastrointestinal tract: commensal, opportunistic, and pathogenic.
Commensal bacteria, such as Bifidobacterium bifidum, Lactobacillus reuteri, and Akkermansia muciniphila, are considered normal bacteria of the human gut microbiome. These bacteria help you to digest your food, absorb nutrients, maintain immune function, fend off against pathogenic bacteria, and support your overall health.
Opportunistic bacteria, such as Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa, are also considered normal, harmless bacteria of the gut microbiome, but only at low levels. Certain factors, such as the overuse of antibiotics and overconsumption of processed foods and refined sugars, can disrupt the balance of the gut microbiome and cause opportunistic bacteria to overgrow and cause symptoms.
Pathogenic bacteria, such as Clostridium difficile, Escherichia coli, and Yersinia enterocolitica, are harmful bacteria that are typically acquired through consumption of contaminated food or water. These bacteria tend not only to cause digestive symptoms, but can also impair immune function, which sets the stage for other infections to activate and proliferate and cause other symptoms outside of the digestive system.
Fungi
Fungi are microorganisms that, like bacteria, can either benefit or harm the host. Unlike bacteria, however, which are predominantly commensal, most fungi in the human gut microbiome are opportunistic. The qPCR stool analysis tests for the most common species of opportunistic fungi in the gastrointestinal tract that tend to cause chronic symptoms if overgrown, such as Candida albicans, Saccharomyces cerevisiae, and Rhodotorula mucilaginosa.
These fungi typically don’t overgrow unless your gut microbiome is disrupted or immune function is impaired, so restoring gut microbiome balance and immune function should almost always be prioritized over an eradication protocol.
Viruses
Viruses are microorganisms that multiply only by invading the cells of other organisms. The qPCR stool analysis tests for two viruses in the gastrointestinal tract that tend to cause symptoms if activated: Epstein-Barr virus and Cytomegalovirus.
Most viruses that you come into contact with don’t activate, however, and rather exist in a latent stage until something suppresses your immune function, such as a parasitic, bacterial, or fungal infection, at which point they can activate and cause chronic symptoms that range from mild to completely debilitating.
Intestinal permeability
Intestinal permeability is the mechanism by which your small and large intestines absorb nutrients (useful substances) while protecting your body from pathogens, toxins, and antigens (harmful substances). Your intestines are able to do this because they’re lined with a layer of cells—intestinal epithelial cells—that provide a selective barrier to control what substances can and cannot enter your bloodstream.
If the junctions between intestinal epithelial cells are intact, intestinal permeability is normal, and useful substances will be absorbed, and harmful substances will not be absorbed. If the junctions between intestinal epithelial cells become compromised and widen, however, intestinal permeability is increased, and parasites, bacteria, fungi, viruses, metals, chemicals, food antigens, and other harmful substances will be absorbed into circulation, which ultimately causes damage to the body that manifests as chronic symptoms.
The qPCR stool analysis evaluates intestinal permeability by measuring zonulin (a protein responsible for regulating intestinal barrier function).
Immune function
Your immune system is a complex network of cells, tissues, and organs that work together to protect you from parasites, bacteria, fungi, and viruses that would otherwise cause harm. Just as the network of cellphone coverage isn’t equally distributed throughout the world, and tends to be concentrated in areas of high population density, the complex network of your immune system also isn’t equally distributed throughout your body, and is instead concentrated in the areas that need it most.
Your intestines harbor 70% of all immune cells, for example, to keep up with the endless onslaught of pathogens that you (unknowingly) ingest.1 While your thymus, bone marrow, lymph nodes, lymph vessels, and spleen are also critically important to the production and regulation of your immune system, your intestines—your gut microbiome, in particular—disproportionately influence your immune function and overall health.
The qPCR stool analysis evaluates immune function in the gastrointestinal tract by measuring secretory IgA (an antibody that protects the intestinal barrier), anti-gliadin IgA (an antibody to gluten), and eosinophil activation protein (a marker of inflammation).
When you should consider a stool test
If you have chronic digestive symptoms, doing a stool test might be one of the first things you or your practitioner think of. It’s an obvious focus—digestive symptoms are a likely indication that the digestive system is compromised in some way—and it doesn’t require any extreme out-of-the-box thinking to rationalize moving forward with such a test.
But if you don’t have digestive symptoms, and instead have other symptoms seemingly not connected to or influenced by the digestive system, the importance of doing a stool test might be less obvious. It might seem far-fetched that a symptom in one part of your body could be caused by something being off in another part of your body. And it might be difficult to rationalize doing a stool test when there are probably other tests that are more specific to your symptoms that should take precedence.
There’s also the fact that collecting a stool sample isn’t particularly fun, which certainly makes it easy to come up with all sorts of reasons as to why you shouldn’t do a stool test, or to put if off indefinitely.
I think the best approach, if you have chronic symptoms, is to try to put these reservations aside, and to instead assume that your symptoms are either directly or indirectly caused by factors in your gastrointestinal tract—parasites, bacteria, fungi, viruses, intestinal permeability, or immune function—and to proceed with testing accordingly. If your test results are normal, then you’re in the infinitesimally small minority of people with optimal digestive health. More likely, you’re in the majority of people with suboptimal digestive health, and you’ll learn about factors that are causing your symptoms that no saliva, blood, or urine test could ever reveal.