313: Testing for Candida Overgrowth (Is the Candida Spit Test LEGIT?)

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Testing for candida when you have what you think is a candida rash can feel really discouraging. Especially when you have all the classic signs of candida overgrowth, and yet, your test comes back “clear.”

What a frustrating waste of time and money, right?

These results probably leave you feeling like you don’t know where to turn, or what’s causing your rash. 

And maybe you’ve even got symptoms of a fungal skin infection that don’t match up with test results. Now what?

Well first off, your test results may be accurate — maybe Candida isn’t at the heart of what’s going on with your skin. 

But it’s absolutely possible that Candida is lurking under the surface…meaning that your test results aren’t exactly accurate. 

In this episode, I’m digging into the complexities of testing for Candida and why you can’t always trust the results. 

Just know that if you’re looking for answers and struggling to figure out exactly what’s causing your rash, there’s a way to stop throwing money away on tests that come back with inconclusive results.

I outline these tests in my Skin Rash Root Cause Testing Guide here to help you uncover which tests may help you the most (as well as how to order them). 

So, let’s talk about testing for candida overgrowth, and why you may be getting a false negative with your candida test results. 

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In This Episode:

  • How to test for candida and fungal overgrowth
  • The best test for candida (this will surprise you!)
  • The worst test for candida (it’s a worthless recommendation)
  • Is the candida spit test accurate?
  • How to deal with a yeast fungal skin infection or gut overgrowth


“Urinary Organic Acid test is not the same as a Mycotoxin test, and cannot replace the information gathered through a mycotoxin test. So they are NOT interchangeable.”

“Yeast (fungal organisms) are extremely hardy. They’re “survivors” that can outlast your attempts to starve them through die and may even evade different treatment options.”


medical tests for candida

Testing For Candida Overgrowth {FULL TRANSCRIPT}

Welcome back to episode 313 of the Healthy Skin Show! In today’s episode, we’re going to talk about testing for candida overgrowth AND which tests are the best and worst at detecting candida overgrowth.

To kick things off, let’s start with a quick rundown of candida fungal skin infections and internal overgrowth, AND how you may arrive at the conclusion that a yeast/candida overgrowth is the culprit behind your rashes.

Candida overgrowth can cause:

  • Eczema-like skin rashes typically with very clearly defined borders
  • A distinct increase in itchiness at night
  • Other symptoms like vaginal yeast infections, thrush, and intense cravings for sugar

Candida can also show up in various areas on your body that are more likely to be moist and/or dark – in places where fungus likes to grow. 

In my practice, candida overgrowth can be a factor in various different skin problems including eczema, psoriasis, rosacea, chronic hives, dermatographia, tinea versicolor, and dandruff.

Some of the common fungal overgrowth “hotspots” can include rashes in or on:

  • Your armpits
  • The back of your neck
  • Under your breasts
  • Back of your knees 
  • Inside of your elbows

Or maybe you’ve been diagnosed with or suspect you have psoriasis. Psoriasis has been linked to increased levels of Candida and some research indicates treatments for psoriasis may further increase the risk of candida infection or overgrowth.(1,2,3,4) And it may play a role in inverse psoriasis too!

Even seborrheic dermatitis has connections to internal fungal overgrowth in addition to immune reactivity issues in the skin microbiome with Malassezia.

It’s important to point out that you may have a candida skin infection but none of the other signs and symptoms of candida overgrowth

So, now that we’ve reviewed what might make you suspect Candida is the culprit behind your rashes, let’s look at different options when it comes to testing for candida

For a deeper dive into causes of candida overgrowth, check out episode #311 HERE.


woman wondering how to test for candida

How Can You Test For Candida?

Is there a test for Candida that will definitively prove candida overgrowth is the reason you’re itchy and breaking out in a rash?

Let’s take a look at the 2 most common test options.


1. Urinary Organic Acid Test For Candida

First, there’s the Urinary Organic Acids Test. This type of at-home test looks for very specific waste products produced by specific organisms. Most commonly, these tests look for arabinose or d-arabinotol

Arabinose is one of the waste products produced by Candida Albicans. So if arabinose is present in your urine, then you would suspect the presence of candida overgrowth

Unfortunately, arabinose and d-arabinotol are not always reliable markers for yeast presence because it isn’t a universal waste product for all forms of yeast and fungal organisms.(5) So it’s possible to miss or underestimate fungal overgrowth if you’re solely basing your conclusion on the results from an organic acid test.

While there are dietary sources of arabinose, I generally haven’t seen that impact the results of the test in my clinical experience.

The other problem with Urinary Organic Acid Tests is the fact that there are many other types of fungal organisms in addition to Candida Albicans that produce arabinose as well as different waste products in your body. 

It’s also worth noting that an Urinary Organic Acid test is not the same as a Mycotoxin test, and cannot replace the information gathered through a mycotoxin test. So they are NOT interchangeable – a point that I’ve verified with labs that offer urinary mycotoxin testing. 

So yes, the test can look clear and may not actually be accurate since there’s so much more that the test can’t pick up. This often results in false negatives. 

Ultimately I believe that while an Organic Acid Test could be a helpful candida overgrowth test, it’s not foolproof. The results always need to be combined with a detailed case history (and even other testing) to help your practitioner offer a clearer answer.


2. PCR Stool Test For Candida

PCR stool tests are another type of test for candida overgrowth in the gut. Two common clinical stool tests include the GI Effects (Genova Diagnostics) and the GI Map (Diagnostic Solutions). 

These are tests that allow you to conduct testing for candida at home. And they are distinctly different from other stool tests that are commonly advertised to you online. To learn the difference between them (and which are the better ones to invest in), check out my Stool Testing Guide.

It’s crucial to know that these tests are large intestine (aka. colon) tests

This is a significant point because candida lives up in the small intestine and can cause something called Small Intestine Fungal Overgrowth (SIFO). 

So in order for candida to be picked up on a stool test, it has to really overgrow in the small intestine significantly first — moving far enough down the colon for it to get picked up on a stool test. 

As a result, PCR stool tests can totally miss Candida and other fungal species providing false negatives. So having no fungal organisms show up doesn’t mean there’s not a problem.

Also, having even some fungus show up “within the normal range” can be viewed as a sign of overgrowth in the small intestine especially when you consider other case details and your case history.

So yes, a PCR stool test could be helpful, but a negative result should be heavily scrutinized especially if you struggle with topical fungal overgrowth (like Tinea Versicolor), confirmed fungal skin infections, vaginal yeast infections, or thrush.


3. Other Tests For Candida Overgrowth

It’s important to mention that there are also tests for candida overgrowth and reactivity that could be helpful. 

The anti-saccharomyces cerevisiae antibody blood test can be very helpful for those dealing with IBD as well as with Hidradenitis suppurativa. Given that IBD can be a co-morbidity of psoriasis, it could also be helpful in certain cases.

There may be some functional use of the Uric Acid blood marker when elevated to suggest a potential fungal gut issue lurking under the surface in the absence of gout symptoms or diagnosis. This is because certain organisms like Saccharomyces cerevisiae produce purines which can increase uric acid.(6)

Fungal overgrowth or infection on the skin can be identified by a skin culture or a faster type of skin scraping test called a KOH preparation. I discussed how this easy in-office test is run with Dr. Peter Lio HERE.

Microscopic exams of stool samples can sometimes yield better results than a PCR stool test, but again, aren’t perfect and can give false negative results.

There are also antibody blood markers for different Candida species responsible for candidiasis infections your doctor could run if it’s warranted given your case.


vials for candida tests

What Is The Best Candida Test?

So what is the best Candida test? The reality is that both of the common types of testing for Candida can show false negatives, and often do.

And that’s why when I’m asked my recommendation for the best Candida test my honest answer has to be – there isn’t one. 

All testing for Candida has drawbacks. 

That’s why case details and your unique case history can be helpful in determining if candida overgrowth is present, and if that’s what’s at the root of your rash (or at least one of the factors at play).

Also, since testing isn’t perfect, you can and should use other diagnoses and clues to help you figure out if candida overgrowth is present

So for example, if you have recurrent yeast infections, thrush, fungal skin infections, or tinea versicolor, testing may not necessarily yield information that will make a difference in how to address what’s going on UNLESS there is a serious infection going on.

Remember, overgrowth is vastly different than an infection (which should be evaluated by a physician and may require treatment). 


analyzing candida spit test with a microscope

Is The Spit Test For Candida Accurate?

One final word on testing for Candida. Maybe you’ve heard of the famous spit test for Candida. This is one of the candida tests you can supposedly do at home for free. 

The idea is that you take a glass of water, spit into it, and then observe how the spit changes over time. According to anecdotal stories, your spit will either grow legs or produce cloudiness in the glass of water depending on whether you have candida overgrowth or not.

Unfortunately, there’s absolutely no scientific evidence to back up the spit test for Candida. 

For this reason, the Candida spit test gets my vote for the worst possible test for Candida.


supplements for treating candida

Candida Yeast Overgrowth Treatment

Candida overgrowth treatment can be tricky and many of the suggestions you’ll see, like the “candida diet” or “sugar-free” diet either don’t work or make your skin rash worse.

Yeast (fungal organisms) are extremely hardy. 

They’re “survivors” that can outlast your attempts to starve them through diet. And even can evade antifungal medications and herbal supplements because they can hide behind something called biofilms for protection.

So while it’s tempting to try different methods to starve yeast, it can drive food fear, increase food reactivity, worsen nutrient deficiencies, and make phase 2 liver detox challenges worse!

That’s why it’s crucial to get to the bottom of what’s actually driving the problem. 

Because honestly, candida overgrowth is the result of something larger – so it could be viewed more as a symptom and not the ONLY problem going on. 

My clinical experience as a nutritionist working with thousands of skin rash warriors has shown me that there are usually 3 to 6 factors that drive your rashes – candida overgrowth being just one of those factors. 

Once you understand what those root causes are, it makes addressing the underlying problem so much easier. Especially if you’re currently taking biologic drugs, JAK inhibitors, or immunosuppressants!

If you’re interested in getting more testing done, I’ve put together a simple guide! Download my free Skin Rash Root Cause Testing Guide here, and it will walk you through which tests could be helpful (AND how you can order them).

I hope my clinical perspective offers clarity about the pros and cons of testing for candida and other factors you need to know so you don’t end up missing clues based on false negatives. 

I hope this empowers you to dig into your case!

If you’ve got any questions or thoughts to share about this, leave a comment below so I can address them.

Thank you so much for tuning in and I look forward to digging deeper with you in the next episode!


woman reading reference book


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5960518/
  2. https://hrcak.srce.hr/file/244401
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4963441/
  4. https://pubmed.ncbi.nlm.nih.gov/25972190/ 
  5.  Bralley JA, Lord RS. Laboratory Evaluations for Integrative and Functional Medicine. 2nd ed. Duluth, GA: Metametrix Institute; 2012; pg 494-7.
  6. https://www.science.org/doi/10.1126/scitranslmed.aaf9044?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

“Urinary Organic Acid test is not the same as a Mycotoxin test, and cannot replace the information gathered through a mycotoxin test. So they are NOT interchangeable.”

Jennifer Fugo, MS, CNS

Jennifer Fugo, MS, CNS is an integrative Clinical Nutritionist and the founder of Skinterrupt. She works with women who are fed up with chronic gut and skin rash issues discover the root causes and create a plan to get them back to a fuller, richer life.

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