Evaluation and assessments are essential for any goal-centered endeavor like when you are looking for the best functional lab testing options.
In fitness, athletes test their mile time or max bench press weight, In school, your math and spelling skills were tested every few weeks to ensure you were gaining knowledge. And in functional medicine, functional lab testing can better help you and your functional medicine practitioner determine the best foods, supplements and lifestyle solutions to help you optimize your health.
If you don’t know where you’ve come from, you don’t know where you’re going.
How Functional Lab Testing Transformed My Health (& Can Do So for Yours Too)
Does the following sound familiar?
Late night Google search: “Natural candida remedies.”
- Oregano oil
- Coconut oil
- Greek yogurt
- Tea tree oil
- Apple cider vinegar
- Probiotic suppositories and supplements
- Boric acid
- Vitamin C
- Hydrogen peroxide
I had tried them all. Nothing worked. At least nothing worked a hundred percent.
The clincher? I didn’t just have candida.
I had mold, mycotoxin, and fungal overgrowth. I had SIBO. I had heavy metal overload. I had mass cell activation syndrome and Th1/Th2 immune dysregulation. I had vitamin B2, manganese, vitamin D, and vitamin A deficiency. I had metabolic endotoxemia.
My body stumped Dr. Google.
I never would have discovered any of these facts until I actually did some functional lab testing with a functional medicine practitioner and stopped guessing, symptom chasing and trying to figure things out on my own (ie. throwing TONS of money at supplements and restricting a new list of foods every week).
Functional lab testing—not guessing, is a fast-track way to stop shooting darts in the dark.
Functional Lab Testing vs. Conventional Lab Testing
Conventional lab testing is lab testing you’d receive if it were ordered by a medical doctor—typically based on what insurance will cover and focused on identifying full-blown disease or the progressed form of a health condition. Conventional tests may include blood work, poop or urine samples, breath tests, imaging and scans, and are great for diagnosing you with a specific ICD-10 diagnostic code the doctor is looking for—like GERD (acid reflux), cancer, E. coli, or heart disease.
Functional lab testing can also help you identify health imbalances in your body. However, unlike conventional lab testing that often looks for a specific issue, functional lab testing is typically more focused on prevention—identifying the patterns and health trends that may collectively lead to disease, or may be the cause behind unsolved, non-specific symptoms.
Put another way, conventional lab testing is more like using a fishing pole and specific bait (the test) to catch a specific fish (a condition)—such as a trout or shark—whereas functional lab testing is more like casting a wide net to see what fish (conditions) are present in the sea.
For example, your doctor may run a conventional stool test to specifically look for a pathogen like E. coli or C. diff in your body. A functional stool test might instead assess over 40,000 microbes and yeasts present in your colon and determine if conditions like dysbiosis, insufficiency dysbiosis (low growth of healthy bacteria), candida, or an unknown pathogen is present.
Both conventional and functional lab tests can be helpful, but since functional testing tends to look at the big picture, it is often most useful for determining seemingly mysterious symptoms that your doctor apparently cannot solve. Some of the most common functional lab tests may include:
- Comprehensive stool analysis
- Organic acids urine testing
- Functional blood chemistry
- Salivary and urine cortisol testing
- SIBO breath testing
- Heavy metals testing
- Mold and mycotoxin testing
- Food intolerance testing
- Genetics, DNA, and nutrigenomics testing
How Do You Know What Functional Lab Testing You Need?
It’s important to keep in mind that, just because a lab company promotes a test with studies to back it up, or claims you’ll discover tons of information with which to hack your health, does not mean it’s true.
For instance: food intolerance testing may tell you you’re sensitive to apples, almonds, and broccoli, but is this because you eat these foods every day and you have more of these circulating food proteins in your body already, or because you really can’t eat them? And just because your 23&Me says you have an MTFHR variation in your genes (like 50 percent of the population), does it mean you need to take methylated B-12 and folate supplements, or that instead you should focus on optimizing your epigenetics to influence your genes (your gut health, air quality, nutrition)?
When in doubt, the number one thing I consider when trying to determine if a certain test is the right option is this: Will the results of the test change the treatment protocol?
The answer to that question helps to instantly rule out unnecessary testing. Generally, in terms of testing, less is more.
The Top 7 Best Functional Lab Testing Options
Although there are tons of tests you can run that may be beneficial, I prefer to start as lean as possible and add additional testing if needed.
Here are my top 7 functional lab testing picks I believe a majority of patients can benefit from to heal their root causes.
- Gut microbiome testing: comprehensive stool analysis
- Functional blood chemistry panel
- Wild card lab testing: specific to you (choose one or multiple, depending on your needs)
- Hormone & cortisol testing
- SIBO breath testing
- Intestinal permeability and endotoxemia testing (Cyrex Array 2)
- Gluten-intolerance and gluten cross-reactivity testing (Cyrex Array 3 and/or 4)
- Mold/mycotoxin testing
The reason my number three top test is a wild card is to allow for a little more specificity for each patient, depending on the primary symptoms and chief complaints they come to me with. For example, if you’re experiencing bloating after every meal and an alternating stool consistency, a SIBO breath test may be a beneficial addition to your testing lineup, whereas if you present with symptoms of mold or mycotoxin illness such as fatigue, brain fog, or histamine intolerance, a mold/mycotoxin urine test would make sense. We may even not need to run a wild card test at all.
If, after running these initial tests, you find you’re still hitting ceilings, that is when follow-up testing comes into play.
Functional Lab Test #1: Gut microbiome testing (comprehensive stool analysis)
Before we talk gut testing, let’s set the record straight: There is no one gold standard gut. Every person’s gut microbiome, like their fingerprint, is unique to them. That said, what we do know from research so far is that generally healthy humans seem to have two characteristics in the gut microbiome:
- Bacterial diversity (lots of different strains and types of bacteria)
- Bacterial balance (not too much or too little of any one type of bacteria)
As a whole, the more varied, abundant and homeostatic (balanced) your gut microbiome, the better. Gut microbiome testing gives you a sneak peek into the bacteria living inside your gut.
How Stool Testing Works
Taking a poo test at home is as simple as collecting a fecal (poo) sample and sending the results to a lab for analysis. Lab companies send you the collection tubes, scoops for your poo and collection trays, and gloves to keep things clean.
There are 2 primary types of stool testing techniques:
1. High Complexity Stool Culture
2. Genetic or “Molecular” Stool Testing
High complexity stool culture, in particular, provides in-depth information about gut dysbiosis, insufficiency dysbiosis (low growth of healthy bacteria), inflammatory, nutrient and absorption markers—at least for the 14,000 bacteria that are currently in most labs’ database.
On the other hand, genetic stool testing for your gut—like gene testing for your human genome—snaps a picture of the genes present in your biome and is like is like taking a fingerprint sample of your gut microbiome to see what different species may be there, or what species have been there before. Genetic stool testing is the most common methodology used in conventional medicine practices and some commercial labs, and is best for identifying a specific pathogen, like Cryptosporydium or Salmonella, especially if you or your doctor suspect a specific gut infection or virus. Like high complexity stool culture, genetic stool testing can help you determine if your gut is out of balance, but typically only if the results show a significant percentage increase or decrease in the bacteria that show up on results.
Recommendation: Comprehensive Stool Analysis + Parasitology x 3
Test: Comprehensive Stool Analysis + Parasitology x 3 (Doctors Data) OR GI Effects (Genova)
What it is: Currently offers the most comprehensive assessment of GI markers aside from pathogens or simple bacteria identification.
Order Here: Doctor’s Data Test or GI Effects
Functional Lab Test #2: Functional blood chemistry panel (rhea, can you make all of these toggles instead of text for each marker below?)
Bloodwork is the most used type of testing in both conventional and functional medicine settings—giving you a great, customized baseline into assessing the biochemistry patterns, nutrient deficiencies, disease and health markers at play in your body.
Beyond a standard panel, here are the top markers we assess on a functional blood chemistry test and what they tell you. (See the Functional Reference Range Chart to know the ideal ranges for each).
CBC (Complete Blood Count)
Red Blood Cells, White Blood Cells, MCV, Hemoglobin, Platelets
Measures the cells that make up your blood: red blood cells, white blood cells, and platelets. Most doctors use a CBC to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia; but markers can also show if you are getting enough oxygen in your body—especially red blood cells and MCV (essential for gut healing), as well as if there is a chronic infection or immune condition going on inside (parasite, illness, Lyme, autoimmune conditions, cancer). High white blood cell count would point towards an acute (recent) infection, acute stress or chronic inflammatory conditions (e.g., rheumatoid arthritis, Crohn’s disease, ulcerative colitis, vasculitis); whereas a low white blood cell count would point towards a longer-term infection, greater susceptibility to infections and immune weakness and post-infection recovery.
CMP (Complete Metabolic Panel)
Glucose, Total Protein, Albumin, Calcium, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Bilirubin, Alkaline Phosphatase, AST, ALT
Measures the current status of your metabolism, including the function of the kidneys and liver, electrolyte and fluid balance, blood glucose and blood proteins.
Can also show the current function of the pancreas, gallbladder and liver, indicating gallbladder disease, as well as pancreatitis, fatty liver and non-alcoholic fatty liver.
Cholesterol, Triglycerides, High-density lipoprotein (HDL), Low-density lipoprotein (LDL).
Evaluates cholesterol, triglycerides, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Contrary to popular belief, cholesterol is an essential component for all of our cells and provides structural integrity to cell membranes—it makes our cells strong. Cholesterol is also necessary for the production of bile acids, vitamin D, cortisol and sex hormones (translation: we need cholesterol for healthy hormones and cells). High Total Cholesterol (above 220), or high LDL (often called the “bad” cholesterol”) first suggest “inflammation in the body” and in the liver—not necessarily heart disease. High cholesterol often stems from environmental toxins, certain medications or birth control, dietary imbalances, chronic stress and/or an imbalanced gut microbiome. To further evaluate for heart disease markers and genetic susceptibility to high cholesterol, checking your LDLp (particle number) is the gold standard marker and may be a follow-up test if cholesterol markers are “off.”
Functional Reference Range
Cholesterol: Male: 150–220 mg/dL Female: 150–230 mg/dL
Triglycerides: 50–100 mg/dL
High Density Lipoprotein: 50–85 mg/dL
Low Density Lipoprotein: 0–140 mg/dL
CRP-hs (high sensitivity C-Reactive Protein)
Used to evaluate both chronic and acute inflammation (such as gut inflammation, cardiovascular inflammation, iron overload, etc.).
Functional Reference Range: 0–1 mg/L
A blood sugar balance marker to see how well your body and gut bacteria are balancing your blood sugar. Also a marker for detecting absorption and nutrient status, cortisol imbalances, inflammation and HPA Axis Dysfunction. Ideal levels of glucose are between: 75–85 mg/dL.
HgA1c (hemoglobin A1C)
Gives you the “big picture” of your blood sugar balance. Results reflect your average blood sugar level for the past three months. Specifically, HgA1C measures what percentage of your hemoglobin — a protein in red blood cells that carries oxygen — is coated with sugar (glycated). High levels indicate impaired glucose tolerance and insulin resistance—often due to dietary, absorption and/or gut bacteria imbalances (remember, our gut bacteria dictate our blood sugar levels based on what they absorb and digest). The ideal HgA1c functional range is 4.6–5.3%.
Complete Thyroid Panel
TSH, T4, T3, Free T4, Free T3, Thyroid Antibodies
A complete thyroid panel looks at how your body’s metabolic mothership (your thyroid) is functioning, as well as reasons why it may not be working if it is off.
Vitamin D, 25-hydroxy
A hormone-like vitamin that reflects your body’s ability to absorb nutrients as well as your immune function and thyroid function—all actions that stem from your gut. Low 25-hydroxyvitamin D (below 35) arises from decreased liver function, low sunlight and fresh air exposure, certain drugs, impaired kidney function, thyroid issues, gut dysbiosis, and poor absorption. The ideal functional range for Vitamin D is 35–60 ng/mL.
Vitamin B12, MMA & Homocysteine
Vitamin B-12 is crucial for digestion, healthy red blood cells, nervous system and neurological function (regulating mood, thinking clearly, low anxiety, etc.). The majority of B-12 is produced by gut bacteria, and also consumed in food—primarily animal protein sources (red meat, chicken, organ meats). Low serum Vitamin B-12, along with high methylmalonic acid (MMA) and/or high homocysteine, can all be signs of low Vitamin B-12 production by gut bacteria, poor absorption of B-12 in food and/or low dietary intake. Be warned: vitamin B12 deficiency can be masked by sufficient levels of folate. One way to distinguish between folate and vitamin B12 deficiency is to simultaneously assay serum concentrations of homocysteine and methylmalonic acid. Serum homocysteine and MMA levels will be elevated in vitamin B12 deficiency, whereas folate deficiency will only increase homocysteine levels in the serum, not methylmalonic acid levels. Optimal Vitamin B12 levels are between 450–2000 pg/mL; for MMA < 300 nmol/L; and homocysteine, < 7 µmol/L
Folate is one of the B-vitamins and is needed to make red and white blood cells in the bone marrow, convert carbohydrates you eat into energy, and produce DNA and RNA (your genetic expression). Low Folate, like low B-12, on bloodwork indicates low dietary intake and poor gut absorption or production of this vitamin Folate is found in romaine lettuce, spinach, asparagus, turnip greens, mustard greens, parsley, collard greens, broccoli, cauliflower, beets, lentils and organ meats. Intestinal bacteria in the colon also produce substantial amounts of folate.. Be warned: Folic acid supplements are not the same thing as folate. Folic acid is unnatural, and unlike natural folates, which are metabolized in the small intestine, folic acid found in supplements is first processed in the liver and may result in unnatural levels of unmetabolized folic acid entering the systemic circulation, connected to cancer and inflammation. Ideal is Ideal: > 8 μg/L.
Complete Iron Panel
Iron, Iron Saturation, Hemoglobin, Ferritin, UIBC, TIBC
Too little or too much iron does not do a body good. Iron is an important component of hemoglobin—the substance in red blood cells that carries oxygen from your lungs to transport it throughout your body. If you don’t have enough iron, your body can’t make enough healthy oxygen-carrying red blood cells. If you have too much iron, your blood gets sticky, your body gets inflamed and your organs can “rust” inside.
A complete iron panel assesses for both iron deficiency (“anemia”) and iron overload. Unfortunately, many labs just look at Hemoglobin and Iron markers alone—the two least sensitive markers of iron in the body, often only low or high, in the final stages of iron imbalances. Other markers, particularly UIBC, TIBC, iron saturation, and ferritin—the storage protein for iron—can show you signs of iron deficiency or overload much earlier. Ferritin stores and slowly releases iron in a non-toxic and controlled way, which helps protect against iron deficiency and iron overload.
Zinc is a trace mineral that is essential for the proper function of over 200 enzymatic functions in the body—gut motility and digestion included. Low levels often occur in tandem with digestive dysfunction (IBS, diarrhea, poor absorption from food), slowed growth and development, hormone imbalances, anxiety, poor immune function, and chronic stress. High levels of zinc often occur in conjunction with low copper levels—another mineral in the body vital for immune health and oxygenating the body. Intestinal absorption of copper is inhibited by high levels zinc within the gut and vice versa.
Recommendation: Functional Blood Chemistry Panel
Test: Functional Blood Chemistry Panel through your doctor or a 3rd party lab under the guidance of a functional medicine practitioner.
Investment: $700-$1300 for a complete panel (cash pay)
What it is: Provides you with a comprehensive overview of multiple systems and imbalances.
Functional Lab Test #3: Hormone & cortisol testing
Stress goes far beyond just feeling stress in your head over a work deadline or rush hour traffic.
Circulating hormones throughout your body—like cortisol—also play a role in how your body experiences stress and homeostasis (balance). This hormone is constantly circulating throughout your body, influencing things like the balance and production of other hormones, blood sugar levels, cell metabolism, inflammation, detoxification, digestion, neurotransmitter signaling and the “stress response”—such as the rise in blood pressure and heart rate in the face of a threat.
Enter: cortisol hormone testing, a great lab testing tool for understanding your current physiological hormone patterns—particularly cortisol— as you continue to hack stress and optimize your health.
There are multiple ways to assess cortisol, however, like other testing methods, not all tests are created equal. Options include:
- Hair Testing
- Serum Testing
- Saliva Testing
- Urine Testing
Recommendation: Saliva, Urine & Blood Testing
Test: Dutch Plus (Urine & Saliva) Test + complete hormone bloodwork in your Functional Blood Chemistry Panel
Investment: $499 + bloodwork
What it is: A combined urine and saliva test that gives you a complete picture of both free and total cortisol, as well as other sex hormones, neurotransmitters, melatonin and cortisol metabolites—the metabolized (active or actually used) forms of cortisol.
Order Here: Dutch Plus
Functional Lab Test #4: SIBO breath testing
Small intestinal bacterial overgrowth is the overgrowth of bacteria in your small intestine. While we all have bacteria in our gut, the majority (about 90%) of bacteria should be in the large intestine, not small intestine. SIBO is a symptom of gut disruption caused by several factors including: low stomach acid, carbohydrate malabsorption, birth control pills, chronic stress.
There are three primary types of SIBO: Hydrogen-based SIBO triggers more bloating, gas, IBS and loose stools, whereas methane-based SIBO is associated with constipation; and hydrogen-sulfide SIBO tends to result in rotten egg smelling gas, IBS or constipation and a sensitivity to high sulfur foods (like proteins and certain veggies, such as broccoli and Brussels sprouts). Other side effects of both types include: gas, skin breakouts, allergies, low immunity, hormonal imbalances, thyroid imbalances, malabsorption, food intolerances and nutrient deficiencies (especially vitamin B12, vitamin A, vitamin D, and vitamin E).
To date, SIBO breath testing is the most widely used snoninvasive test method for suspected SIBO. Breath testing is based on the concept that bacterial fermentation of non-absorbed carbohydrates is the culprit behind exhaled hydrogen and/or methane gas in the breath. There are two types of breath tests: Glucose or Lactulose Breath Testing.
To take the test, the patient either ingests a Glucose or Lactulose based carbohydrate then breathes into a tube every 30 minutes over the course of 3 hours. Both tests assess methane and hydrogen gas levels in the upper GI, however there are slight differences: Glucose testing is more specific, but less sensitive; in other words, it has a higher rate of false negatives and a lower rate of false positives. Lactulose testing is more sensitive, but less specific; it has a higher rate of false positives and a lower rate of false negatives.
Despite both tests’ limitations, hydrogen and methane breath testing remains the best option for diagnosing SIBO in clinical practice.
Recommendation: Lactulose SIBO Breath Test
Test: Genova Lactulose Breath Test
What it is: A high spike in the hydrogen over 20 ppm at any point in the test, and/or a spike in methane gas levels over 12 parts per million (or even over 3 ppm according to some criteria).
Order Here: Genova Lactulose Breath Test
Functional Lab Test #5: Micronutrient test
Almost every physiological function in your body requires micronutrients to function optimally. Vitamin, minerals and anti-oxidants play a key role in:
- Producing and releasing energy.
- Strengthening the immune system.
- Reducing systemic inflammation.
- Protecting against free radical damage and cancers
- Maintaining a healthy hormone balance, gut health and blood sugar
Whole blood cell micronutrient testing can help with identifying functional deficiencies in intracellular micronutrient levels, excesses of nutrients caused by uncontrolled supplementation, and Providing a long-term nutritional status of the previous 4-6 months.
Recommendation: Micronutrient Whole Blood Testing
Test: Vibrant America Micronutrient Test or NutraEval
What it is: While taking vitamins can be extremely beneficial, everyone has specific nutritional needs. It is important to understand which supplements are right for your body and your circumstances so that you don’t waste money on items that could be unnecessary or even harmful. This blood based nutrient test will help you determine what imbalances may be present in your vitamins and minerals, contributing to how you feel.
Order Here: NutraEval Note: Vibrant America must be ordered through a practitioner
Functional Lab Test #6: Gluten-intolerance & gluten cross-reactivity testing
Not all food intolerance tests are beneficial; nor are they created equal.
Food Intolerance Testing Problems
For one, if you go to your conventional doctor for a check-up and ask them for a food sensitivity test, they will test you for a food allergy—IgE antibodies— that are an immediate reaction to foods; they don’t test for delayed reaction and food sensitivities (IgG, IgA, IgM)…so you’ll still be left in the dark.
Number two, most food sensitivity tests are not the gold standard. The majority of sensitivity tests only test foods in the raw—not cooked—forms.
Dietary proteins change their immune reactivity if they’re cooked or raw… For example, sensitivity to bacon increases ten times when it is cooked versus raw…But raw bacon, who eats that? Eggs or chicken may show up positive…but how many people eat raw egg or raw chicken— or even raw broccoli vs cooked…
Number three: Most food intolerance tests do NOT show cross-reactivity foods. For example, if a person reacts to cow’s milk, 92 percent of people will also react to goat’s milk and cheese because they have the same amino acid structure…If you react to melon, there’s a 92 percent chance you will react to avocado, fruits, or watermelon…
For all these reasons, most food intolerance tests on the market only give you a piece of the puzzle… That said, if you DO want to test yourself food sensitivities, I only recommend the gold standard lab: Cyrex Labs–well known for its high standards and ELISA testing methodology.
Recommendation: Cyrex Food Intolerance Testing
Test: Cyrex Array 3X, Array 4 &/or Array 10
What it is: The Gluten and Gluten-Associated Cross-Reactive Foods & Foods Sensitivity Screenings (Array 3X and 4) identifies reactivity to foods known to cross-react to gliadin and reactivity to newly introduced foods on a gluten-free diet. The Multiple Food Immune Reactivity Screen (Array 10) evaluates immune reactions to 180 raw and/or modified foods, food enzymes, lectins, and artificial food additives, including meat glue, colorings and gums. It can detect dietary-related triggers of autoimmune reactivity and monitor the efficacy of customized dietary protocols.
Order Here: Cyrex Arrat 3X, Cyrex Array 4, Cyrex Array 10 OR ALL 3 Tests in one
Note: Not currently eating gluten and stay clear of eating out regularly? Cyrex Array 3X may not be necessary. For the most complete picture, order all 3.
Functional Lab Test #7: Mold/mycotoxin testing
Mold and mycotoxin illness can happen to anyone. Mycotoxins are toxic metabolites from mold and fungi that act like poison to the body and are capable of causing disease and a host of side effects including: nausea, GI disturbances, hair loss, allergies, asthma, brain fog, memory loss, wheezing, watery eyes, itchy, skin irritation, chronic sinusitis, shortness of breath, anxiety, light sensitivity, numbness in hands and feet and sore throat.
Mold and mycotoxins can grow inside your body especially inside body cavities like nasal passages and sinuses, the a perfect warm, moist environment.
A mycotoxin urine test is a great way to triage if mycotoxins and fungal overgrowth may be a key driver in your health issues. However, be warned: sometimes folks with mold illness are NOT good detoxifiers, so test results may not show up until you begin detoxing if mold is suspected.
Recommendation: Mycotoxin urine test
Test: Great Plains Labs Mycotoxin Urine Test or Real Time Labs
What it is: The mycotoxin analysis tests for over 10 different mycotoxins from 40 species of mold. Great Plains uses Mass Spectrometry which can detect very low levels of mycotoxins, whereas Real Time uses ELISA testing, a very sensitive detection method using antibodies (autoimmune-like reactions) prepared against mycotoxins. Practitioners often run the tests side by side since the testing methodology is different and can paint a complete picture of the mycotoxin problems.
Order Here: Great Plains or Real Time
Don’t Go it Alone
One of the most important steps for running lab tests and addressing findings appropriately is to work with a skilled practitioner.
You can have use the best testing methods and find out the most information in the world, but if you choose the wrong practitioner, you probably won’t get the proper therapeutic program. I recommend working with a practitioner who practices and regularly studies Functional Medicine—a scope of practice utilized by some medical doctors, osteopathic doctors, and allied health providers (nutritionists, dietitians, therapists, health coaches).
Functional medicine specially trained practitioners aim to help patients identify the root cause(s) of chronic, lingering, or apparently unsolvable health issues, and to help prevent disease and optimize your health—not just address symptoms.
You want a practitioner who focuses on fully understanding your health history (not just your immediate health history) and the lifestyle factors (nutrition, supplements, sleep, exercise) that contribute to both wellness and disease.
You also want a practitioner who doesn’t run every test under the sun or prescribe supplements or programs with little guidance.
Reach out to the Thrive Wellness virtual clinic for guidance and support today.