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What Is Candida? 5 Facts You May Not Know

Written by Dr. Michael Ruscio, DC on November 18, 2024

Written by Dr. Michael Ruscio, DC on November 18, 2024 — Reviewed by Hilary Watts

• Candida is Common|
• Tests Aren’t Helpful|
• Overgrowths Don't Happen in Isolation|
• Eating Low-Carb Isn’t Mandatory|
• Antacids Could Be Making It Worse|
• 4-Step Plan to Beat Candida|
• More Effective Treatment|

Candida is a yeast, a type of fungus, that can populate our skin (think armpits), digestive tract, and reproductive system, and it may sometimes cause infections. Symptoms like bloating, gas, diarrhea, skin issues, genital and vaginal yeast infections, and depression may all point to a Candida overgrowth. 

However, there are several myths and misconceptions around what Candida is and the role it plays in the body. In light of more recent research and new knowledge about the microbiome, it’s likely that Candida overgrowths in the gut have been over-diagnosed.

That’s not to say that intestinal Candida overgrowths can’t happen—they can in both the small and large intestines. But over-focusing on this specific microorganism makes it easy to miss the bigger picture: the health of the gut and its diverse ecosystem of microbes.

In this article, I’ll correct some of the inaccuracies around Candida. Then I’ll share a simple research-based plan for getting rid of excess Candida in the intestines while bringing the gut microbiome back to balance.

Fact 1: Candida is a Common—Even Friendly—Gut Resident

Candida is a yeast (a type of fungus) that resides in most people’s guts, usually without causing problems. In a recent study of stool samples, researchers found Candida albicans (the most common Candida species in humans), in the stool of about 577 (83%) of 695 healthy people 1.

This suggests that Candida is a normal part of the ecosystem of microbes in our gut, and it may even be beneficial when it coexists peacefully with other microbes.

So, how did Candida get such a bad rap? One reason could be that when Candida infections do occur, they can cause some pretty well-known and miserable symptoms. 

For example, both vaginal thrush (vaginal candidiasis) and oral thrush (oral candidiasis) are caused by a Candida infection (usually Candida albicans). 

Candida can also cause invasive candidiasis, a severe infection (sometimes life-threatening) that occurs in very sick patients and those with a weakened immune system, affecting the blood, heart, brain, eyes, and bones. And many parents are familiar with Candida diaper rash in babies. 

Given that Candida can cause these unpleasant conditions, it’s easy to assume that if this type of yeast is in the intestines, it must be producing gut symptoms, too.

On a more cynical note, there’s a big market on the internet for Candida testing kits and Candida-killing supplements. Those who are pushing these kits have a vested interest in making us believe Candida is the main factor behind our symptoms.

In reality, what’s important to gut health is the overall balance of microbes in the gut, not just whether Candida is present. In particular, having a robust and diverse population of bacteria in the gut is what keeps Candida numbers in check 2.

In other words, by focusing on keeping our microbiome as a whole, healthy ecosystem, we don’t need specialized actions to get rid of intestinal Candida.

Fact 2: Tests for Intestinal Candida Aren’t Helpful

I  don’t use stool tests to quantify intestinal Candida for three reasons. 

First, Candida is commonly found in the stool of healthy people and is no cause for alarm 1. 

Second, there are no established standards for what a “normal” or “high” level of Candida is in the gut. So, two labs might measure the same level of Candida in a stool sample, but one may define the level as normal, while the other might label it as high.

For example, scientific researchers studying Candida populations in the gut have suggested that at least 10,000 to 100,000 colony-forming units (CFU) indicate a high amount of Candida 3 4. In contrast, functional medicine labs may not provide a normal value, or they may suggest that anything over 5,000 CFU is too much 5. 

In other words, there is no standard agreement on what is high and what isn’t, so it’s better to use symptoms to guide treatment 6. 

The third reason I don’t use stool tests to measure Candida is that there’s a lot of inconsistency in test results from lab to lab. For example, at the clinic, we split one clinician’s stool sample in two and sent each half to a different testing center. 

In the same stool sample, one lab found an overgrowth of Candida while the other lab did not. There were also huge differences reported in the amount of other species in the stool, including Akkermansia, Klebsiella, and Pseudomonas.

As a side note, urine and blood test tests that check for d-arabinitol (a Candida-made sugar that we excrete in the urine) may have partial validity for diagnosing  invasive candidiasis, a serious infection 7. However, these tests are not validated for assessing intestinal Candida.

To recap, with gut Candida tests being so inaccurate and unreliable, I no longer use them. Instead, I recommend that my clients use their symptoms as a barometer to help us guide their treatment. In fact, research shows that intestinal Candida overgrowth and symptoms may correlate closely 6. 

In general, gut symptoms indicate a problem with the whole intestinal ecosystem, of which Candida is simply an interdependent part.

Fact 3: Candida Overgrowths Don’t Usually Happen in Isolation

When we help clients at the clinic, we often find that a Candida overgrowth in the gut is a symptom of a more generalized problem with their microbiome health. 

Although this observation is anecdotal, we also have data supporting the idea that microbiome imbalances occur together. 

For example, one study involving 150 participants with chronic gastrointestinal (GI) symptoms linked with overgrowths found that 34% of the group had a mixture of small intestinal fungal overgrowth (SIFO) and small intestinal bacterial overgrowth (SIBO) 8. 

In other words, Candida yeast and unhealthy bacteria were commonly overgrowing together in the small intestine.

A helpful way to think about this is that it doesn’t really matter if we have SIFO, SIBO, or some other type of gut imbalance. If we’re having a host of gut symptoms, it’s likely our microbial ecosystem as a whole has shifted toward a less healthy composition. 

The way to resolve this is to improve gut health and general health without getting lost in trying to treat one specific gut microbe. Usually, if one is out of balance, it means the others are, too.

Working on underlying gut health can help bring the whole gut microbiome into better balance, which prevents symptom-causing overgrowths and negates the need to find a specific culprit.

Fact 4: A Low-Carb Diet Isn’t Mandatory for Treating Intestinal Candida 

The idea that you have to eat a low-carb diet if you have intestinal Candida—even if you find low-carb doesn’t suit you—is entrenched within the field of functional medicine. I’ve had clients who—based on a Candida overgrowth stool test from 1–3 years prior—stuck to a low-carb diet that clearly didn’t work well for them. 

I find this disturbing because we know that gut Candida tests are inaccurate and unhelpful and low-carb diets are unnecessary.

Case in point: In a study of Candida treatments, a whole-foods diet (with grains, cooked potatoes, and brown rice) along with the antifungal medication nystatin was twice as effective as nystatin combined with a regular diet that included more added sugar and processed foods 9. 

This suggests that the whole-foods diet played an important role in reducing Candida overgrowth, even though it included unprocessed carbohydrates. In other words, not all carbohydrates will worsen an overgrowth of intestinal Candida!

 Not only did the participants eat whole grains and starches, they also avoided alcohol and meats other than fresh fish and lean chicken. It makes sense that this diet helped treat Candida because we have evidence that the opposite—a Westernized, processed diet—can encourage gut fungus to grow out of hand 10. 

The point is that a super-restrictive “anti-Candida” diet that excludes all carbs is not necessary. For most people, simply shifting to a healthy diet that’s low in processed foods and added sugars is enough. 

I’ll touch more on dietary patterns that can help to rebalance the microbiome and keep Candida in check in the 4-point plan below.

Fact 5: Antacid Use Could Be Making a Candida Condition Worse

Stomach acid-reducing medications for heartburn and gastroesophageal reflux disease (GERD) may play a role in intestinal Candida overgrowths and infections. These medications include antacids (like Tums) and proton pump inhibitor medications (like omeprazole).

We all need a certain concentration of stomach acid to kill excess bacteria and fungi and prevent them from populating our intestines. But acid-lowering medications raise stomach pH and reduce its acidity. High stomach pH can allow too many bad bacteria and yeasts to survive the stomach and seed overgrowths farther down the GI tract 8. 

As a result, our clients who absolutely need acid-lowering medications have to be extra diligent when following the 4-step anti-Candida plan, below. Sometimes they even need to head to step 4 (antimicrobials) quicker than usual.

Other Potential Causes of Candida Overgrowth

Though sometimes unavoidable, antibiotic medications are a well-understood factor in the overgrowth of Candida in the gut. Basically, when we lose beneficial bacteria during antibiotic treatment, Candida levels can start to rise 4. 

In addition to a sedentary lifestyle and highly processed diets, preventable factors that can contribute to the growth of Candida in the gut include smoking and excess alcohol intake 11 12. 

Chronic stress is a less preventable but manageable risk factor for microbial overgrowth and other microbiome imbalances (dysbiosis) 13.

I’ll also note that oral contraceptives for birth control can increase the risk of vaginal candidiasis 14, which may increase the risk for Candida infections in the gut 15.

Bring Balance to the Microbiome and Beat Candida in 4 Steps

From my 10 years of experience with clients who have gut symptoms suggestive of a Candida overgrowth or other microbial imbalances, I find a 4-step plan (below) the most effective. The plan works so well on fungal overgrowths because it strengthens the health of the microbiome overall. 

Each client responds slightly differently to the four steps, and not everyone needs all of them.

Step 1: Make Healthy Diet and Lifestyle Changes

When it comes to Candida, diet and lifestyle changes are the treatment options that make the biggest impact on our clients. In particular, moving away from processed foods with lots of added sugar is very helpful.

Since different diets work for different people, two whole-food options we often present to clients are a Mediterranean-style diet or a Paleo-style diet.

The Mediterranean diet (fresh vegetables, lean meats, oily fish, nuts, olive oil, and whole grains) is low in processed foods and sugar and has been shown to be a microbiome-friendly diet 16. It also has benefits for the cardiovascular system 17, is protective against colon and breast cancer 17 18, and may have benefits for mental health 19.

Many of our clients with suspected Candida overgrowth also do well on a Paleo diet, particularly if their gut symptoms are more pronounced.

Like a Mediterranean diet, a Paleo diet meal plan reduces or eliminates processed ingredients and added sugars. However, it also cuts out potential trigger foods like dairy, gluten, and soy that might promote inflammation, gut dysbiosis, and Candida overgrowth 20 21. 

Along with diet changes, we help our clients incorporate regular physical activity. Exercise can increase gut microbial diversity 22, and more healthy gut bacteria means better control of Candida.

A combination of resistance exercise (weights) and aerobic exercise can increase our chances of living longer and with better health 23. 

If exercising sounds daunting to our clients, we remind them that any movement is better than none, and they can always increase intensity or duration over time.

Another important lifestyle hack for helping a gut microbiome with signs of Candida overgrowth is to reduce stress 24. 

Of course, exercise is a great way to reduce stress while also benefiting the microbiome. Other stress-busters that might improve gut symptoms include meditation 23, yoga 25, and especially time in nature 26. 

Once diet and lifestyle improvements are in place, we use probiotics to double down on any remaining symptoms suggestive of a Candida overgrowth.

Step 2: Probiotics

Probiotics are a perfect fit for tackling Candida overgrowth symptoms because they have antifungal and anti-inflammatory properties, and they can increase the number of beneficial bacteria that keep fungus in check. 

Probiotics may also help to heal a leaky gut 27 and promote a healthy immune response 28. In some cases, probiotics can be as effective as common antifungal medications for treating fungal overgrowths 29 30. 

There’s no need to seek out a specific strain of probiotic that’s best for dealing with anti-fungal infections—the evidence doesn’t yet suggest one is better than another. However, research suggests that a multi-strain approach is best for gut health 31, and we see this in our clients with suspected Candida.

In the clinic, we use a triple-therapy protocol that comprises a blend of Lactobacillus and Bifidobacterium strains, Saccharomyces boulardii (a beneficial yeast), and a soil-based probiotic (Bacillus strains), typically for 2–3 months. 

When clients still have gut symptoms after making changes to their diet and lifestyle and using probiotics, the next step is to give their digestive system a short break with an elemental diet.

Step 3: Elemental Diet

An elemental diet is a tool that can starve remaining Candida and allow gut inflammation and sensitivity to fade. 

This hypoallergenic, anti-inflammatory meal replacement provides fully or partially broken-down nutrients to give the small intestine a rest. Having to work less hard to get nutrients can help fast-track gut repair and quickly restore a healthy immune system response. An elemental diet is one of the most effective ways to reset the gut.

While we don’t have research on using an elemental diet for Candida overgrowths specifically, we do have good data showing it can benefit digestive health conditions related to microbiome imbalances, like inflammatory bowel disease 32 and small intestinal bacterial overgrowth 33. Knowing that, it’s fair to assume that an elemental diet may be useful for fungal overgrowths, too.

The elemental diet is a highly flexible and effective tool for gut issues. 

At the clinic, we’ve found that many people do well with a “half-elemental diet,” in which they replace one or two meals a day with an elemental shake and eat a healthy diet the rest of the time. It’s a good option when people feel like a shake for every meal is a bit too much. 

Others may opt for a 24-hour full elemental diet, followed by a half-elemental diet. Typically, I coach my clients with overgrowths to use an elemental diet for 1–3 weeks. If they still have symptoms suggestive of Candida after their elemental diet term, we move on to the next step.

NOTE: For anyone trying an elemental diet on your own, 4 days is the maximum term I would suggest. If you need to go longer, please only do so with the supervision of a practitioner. 

Step 4: Antimicrobials

Lingering gut symptoms after incorporating the first three steps suggest a stubborn case of microbial imbalance that needs an antimicrobial nudge. 

Antimicrobials include a variety of plant extracts and over-the-counter or prescription medications that can knock out bad bacteria, infectious microbes, and fungal overgrowths 34. 

Natural, plant-based antimicrobials with potential antifungal effects in the gut include: 

• Caprylic acid (a fatty acid that occurs naturally in coconut oil and breast milk) 35
• Artemisinin (from sweet wormwood) 36
• Thymol and carvacrol (in oregano oil) 37

Conventional antifungal medicines include fluconazole, miconazole, clotrimazole, and nystatin. Oral tablet or capsule versions are available for intestinal or systemic infections. They can also come as ointments or creams for fungal infections on the skin, or in suppositories for vulvovaginal candidiasis. 

In general, I prefer to use herbal antimicrobials, which tend to have broad effects and contribute less to the rise of antifungal- and antimicrobial-resistant organisms 38. They are also less likely to have unpleasant side effects 39 or negatively disrupt the gut microbiome 40.

In general, I recommend antimicrobials as a final resort because it is so important to prime the whole gut ecosystem with foundational support first. 

Candida Knowledge Makes For More Effective Treatment

Candida is a natural resident of the gut microbiome that can live peacefully alongside other gut microbes but will sometimes overgrow because of an imbalanced diet and lifestyle.

If you suspect you have an intestinal Candida overgrowth, fixating on special anti-Candida diets or getting your Candida levels down to a particular level as measured by a stool test may not be the best way forward. We’ve found that boosting overall gut health is the most effective way to tackle Candida. 

If you still haven’t completely nailed your symptoms of candidiasis, we are here to help. Check out my book Healthy Gut, Healthy You for my complete Great-in-8 gut healing protocol, or contact us at the Ruscio Institute for Functional Health to schedule an appointment.

The Ruscio Institute has developed a range of high-quality formulations to help our clients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you. The information on DrRuscio.com is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.