Candida and Other Yeast Infections

Understanding the Microbiome and Yeast Infections

There are as many bacterial cells as there are human cells in our bodies (Sender, Fuchs, & Milo, 2016). These microorganisms live on our skin, in our gut, and on our mucous membranes. They synthesize vitamins, break down food into essential nutrients, and regulate our immune system. By feeding your gut bacteria with high-fiber foods and supplementing with probiotics when needed, you’re encouraging “good” bacteria to thrive and play defense against overgrowth of harmful bacteria and fungi.

Unfortunately, there are plenty of things that can disrupt your microbiome, like a weak immune system that doesn’t keep microbes in check or taking too many antibiotics, which can kill off both the good and bad microorganisms in your gut. Eating a poor diet, drinking a lot of alcohol, or having chronically high stress levels may also influence your microbiome. And in the absence of beneficial gut bacteria, certain strains of bacteria, viruses, or fungi can begin to overproduce, creating various health problems.

Types of Yeast Infections and How to Treat Them

Yeast can affect nearly any part of your body—your skin, nails, mouth, genitals, or even bloodstream. We’ve broken down the various types of yeast infections and how doctors conventionally treat them.

Topical Candida

Candida can overgrow on the skin, causing a red rash, scaly patches, swelling, or itching. Typically, these symptoms develop in moist areas of the body such as skin folds, under the breasts, near the groin, the armpits, or between fingers and toes. Topical azole antifungals (medication containing an azole ring, such as clotrimazole or miconazole) as well as polyene medications, such as nystatin, are effective. Be sure to keep the area dry to encourage healing (Pappas et al., 2003).

Nail Infections

Candida and other fungi can also cause rare toenail and fingernail infections. This may look like white, brown, or yellow nails that may break easily or start to crumble. Debris may also collect under the nail, and the nails may be thick and hard to trim. Fungal nail infections are usually painless, but wearing certain shoes may be uncomfortable. Some fungal nail infections will go away on their own, while others need treatment, which can range from an oral antifungal, such as terbinafine or itraconazole, to something more drastic, like nail removal (Pappas et al., 2003).

Oral Thrush

A candida infection of the mouth or throat is called thrush. It generally appears as white, bumpy patches on the tongue, cheeks, gums, tonsils, or throat that can be painful or bleed at the touch. Thrush can also cause sore throat and difficulty swallowing if it spreads further down to the esophagus. To diagnose thrush, a swab is usually taken from the back of throat and studied under a microscope for the presence of yeast. It is treated by oral azole antifungal medications, such as clotrimazole, or oral polyenes, such as nystatin (Pappas et al., 2003).

Thrush is most common in babies, older adults, and people with weakened immune systems. Babies can pass thrush from their mouths to their mother’s breasts during breastfeeding, which may result in sensitive red, cracked nipples, flaky skin, or pain during nursing. The mother and child may both want to be treated with an antifungal, such as nystatin or fluconazole (which are both safe for infants), to provide relief (Pappas et al., 2003).

Vaginal Yeast Infections

Almost half of women worldwide will have a vaginal yeast infection before age fifty (Blostein, Levin-Sparenberg, Wagner, & Foxman, 2017). While the symptoms are uncomfortable—itching, burning, thick discharge—yeast infections are easily treatable. Many people opt not even to see a doctor; they just take an over-the-counter antifungal vaginal suppository, such as miconazole, or use boric acid. It’s also common practice for health care practitioners to diagnose a vaginal yeast infection based on symptoms alone. They may prescribe an antifungal medication, such as fluconazole; you take one tablet by mouth.

If you still have symptoms of a yeast infection after treatment or if the infections continue to recur, you should see a doctor for further assessment. Many women continue to treat themselves with over-the-counter medication but don’t fully clear the infection. You may need more aggressive treatment to kill all of the candida, or it may be “azole resistant”—meaning resistant to miconazole, fluconazole, or similar antifungal medications. Alternatively, you may be dealing with a different, less common strain of candida that requires different treatment (like boric acid). Or your symptoms might be due to a different health issue.

To diagnose you correctly, your health care practitioner should take a vaginal swab for testing. Here’s the tricky part: The vaginal culture could contain candida, but you could just be someone who has naturally high levels of candida in your vagina that don’t cause any problem. In that case, the symptoms could be related to something else, like an STI or bacterial vaginosis (White & Vanthuyne, 2006).

If your doctor does determine that you have a recurrent yeast infection, they may prescribe two weeks of vaginal antifungal medication or two weeks of oral antifungal medication, possibly with a six-month maintenance regimen (Pappas et al., 2003). The ReCiDiF regimen, which consists of decreasing doses of oral fluconazole, has been shown to be quite effective for recurrent yeast infections (Donders, Bellen, & Mendling, 2010). In certain situations, your doctor may also prescribe long-term vaginal boric acid suppositories. You’ll also want to maintain proper vaginal and sexual hygiene while limiting your use of antibiotics to situations where they are needed; see more in the lifestyle section on preventing yeast infections.

Urinary Tract Infections (UTIs)

Most urinary tract infections (UTIs) are caused by bacteria like E. coli, but candida may also cause a UTI. UTIs are characterized by uncomfortable symptoms such as a frequent urge to urinate accompanied by a burning sensation, pain in the lower abdomen, or cloudy, dark urine. Hospitalized patients are at increased risk for candida UTIs due to catheter use, and older adults are at increased risk as well. Treatment includes oral or intravenous fluconazole, intravenous amphotericin B, or oral flucytosine. Discontinuation of catheter use alone may clear up the infection in some patients (Pappas et al., 2003).

Male Genital Yeast Infections

Genital yeast infections are really rare in men, and if they do occur, they are contracted from a woman partner. If a man has sexual intercourse with a woman who has a vaginal yeast infection, they are not likely to develop a yeast infection on their own genitals. However, in the rare case that it does happen, men may experience inflammation of the head of the penis, redness, itching, burning, white patches on the skin, and white, liquid substances on the skin of the penis. Or there may be no symptoms at all. Men who are immune compromised, have diabetes, or are uncircumcised may be more susceptible to yeast infections (CDC, 2015).

Small Intestinal Fungal Overgrowth (SIFO)

A good portion of people with uncomfortable gastrointestinal symptoms that cannot be explained by other diagnoses may be suffering from small intestinal fungal overgrowth. SIFO is a condition characterized by bloating, indigestion, nausea, diarrhea, or gas. It’s not clear what exactly causes SIFO, but people who use proton pump inhibitors may be at a higher risk for it.

To diagnose SIFO, a small sample of fluid from the small intestine is taken via endoscope. Blood or stool tests may also be used, but they are less accurate. For treatment, two to three weeks of antifungal medication are usually prescribed (Erdogan & Rao, 2015). More research into SIFO is needed to determine the causes and most effective treatments.

Invasive Candidiasis

When candida spreads and enters the bloodstream or organs, it is known as invasive candidiasis, which can be very dangerous and has a high mortality rate. Hospitalized patients, infants in neonatal units, and people with compromised immune systems are most prone to invasive candida. To diagnose invasive candidiasis, doctors often do a urine test to determine the levels of d-arabinitol, a metabolite of most candida species. The current front-line treatment option for adults with invasive candidiasis is an IV of echinocandin. Other options include antifungal medications, such as fluconazole or amphotericin B. Unfortunately, the mortality rate from invasive candida remains high, and there are emerging cases of drug-resistant candida, meaning that even after treatment with traditional antifungal medications, the infection persists (CDC, 2019).

Resistant Candida Strains

When standard medications don’t do the job, you may be dealing with a drug-resistant bacteria or fungus, which has become a major public health issue. One such fungus, Candida auris, was discovered in 2009 and has spread in health care facilities in several countries, including the US. While C. auris is rare, it’s also deadly; it infects the bloodstream and causes a serious invasive infection. Patients who are hospitalized or have previously taken antibiotics or antifungals are at the highest risk. While most cases can be treated with an IV of echinocandin, several cases have been found to spread from skin contact even after treatment, and other cases may be completely resistant to treatment with the three classes of antifungal medications. The CDC is working to develop models to contain and manage C. auris and other drug-resistant fungal species (CDC, 2018).

Potential Causes and Related Health Concerns

Yeast infections are caused by an imbalance in the microbiome that allows yeast to thrive. People with compromised immune systems or diabetes are most susceptible to yeast infections. Other diseases may be related to yeast infections—see the new research section for more.

Diabetes

Candida is hypothesized to thrive in a hyperglycemic (high sugar) environment that is characteristic of diabetes. A 2017 study found that glucose encouraged candida cells to grow while fructose, a sugar that is digested more slowly than glucose, decreased candida cell growth (Man et al., 2017). This research was carried out on candida cells in test tubes, and whether this is relevant in the human body is yet to be determined. To learn more about diabetes and treatment options, see our research article on type 1 and type 2 diabetes.

Dietary Changes

You’ll often hear that you should avoid sugar and carbs if you have recurrent yeast infections, but there isn’t enough conclusive dietary research at this point. One promising food that’s being further studied is coconut oil.

Sugar and Carbs

If people with diabetes have a higher risk of candida, then would reducing sugar and carbohydrate intake reduce candida growth? A 1999 study found that adding a moderate amount of refined carbohydrates to the daily diet did not significantly increase candida colonization in most people, but may have increased candida in a small subgroup (Weig, Werner, Frosch, & Kasper, 1999). A 2013 study found that eating carbohydrates was associated with more candida; however, it wasn’t determined whether the culprit was all carbs or just sugars (Hoffmann et al., 2013). Another study from 2018 found that while antifungal medication was effective against intestinal candida over the short term, combining an antifungal medication with probiotics and a diet low in sugar, yeast, dairy, alcohol, and cured meats was more effective in preventing regrowth over the next few months. It’s not clear whether the hero here was the probiotics, the diet, or the many other recommended supplements (Otašević et al., 2018). So more research on how diet affects candida growth is warranted.

Coconut Oil and MCTs

With the rise of drug-resistant candida species, there has been an interest in new antifungals. Of particular interest are coconut oil and MCTs (medium-chain triglycerides), which both have been researched for potential antimicrobial and antifungal properties with promising results. Coconut oil is typically fractionated to produce medium-chain triglycerides—also known as MCT oil. A 2007 study found that coconut oil reduced the growth of various strains of candida, with the strongest antifungal activity against C. albicans (Ogbolu, Oni, Daini, & Oloko, 2007). The relevance of this “test tube” study to the human body isn’t clear, but the results may lend credence to the popularity of oil-pulling, where undiluted oil is swished around the mouth for several minutes. A more recent study from 2019 supplemented preterm infants with medium-chain triglycerides, which significantly reduced their total fungal count (Arsenault et al., 2019). While more clinical research is needed to confirm if coconut oil and MCT oil are potent against candida, it seems like a promising option.

Nutrients and Supplements for Yeast Infections

Probiotics are hugely important to your overall gut health.

Probiotics

To keep your good bacteria healthy and happy, you need to eat plenty of high-fiber foods. If you’re prone to yeast infections or are currently taking an antibiotic, you may want to supplement with a probiotic to support a healthy gut flora. Find one that contains several different Lactobacillus strains—they have been shown to be effective against candida (Matsubara, Bandara, Mayer, & Samaranayake, 2016). A combination of L. rhamnosus, L. acidophilus, Bifidobacterium longum, Bifidobacterium bifidum, Saccharomyces boulardii, and Streptococcus thermophilus was found to reduce the risk of candida infections among children in a pediatric intensive care unit who were on broad-spectrum antibiotics, so a mix of these probiotics may be helpful (Kumar, Singhi, Chakrabarti, Bansal, & Jayashree, 2013). For vaginal yeast infections, there are oral probiotics as well as vaginal probiotic suppositories that may be more useful, but there is not solid evidence to recommend one over the other. Other medications that may weaken the immune system and encourage fungal growth include corticosteroids and TNF inhibitors, so you may want to take a probiotic with these medications too (CDC, 2017b).

Lifestyle Changes for Yeast Infections

It’s important to keep up with personal hygiene and healthy sexual practices to avoid unwanted infections. Also be careful with excessive antibiotic intake.

Personal Hygiene

Within reason, keep your skin clean and dry to prevent candida from growing on your skin. To prevent nail infections, keep your nails clean and trimmed. Wear shoes when using public restrooms. Don’t share nail clippers with other people. If you go to nail salons, be sure they are sanitizing their tools and equipment (CDC, 2017a).

To maintain a healthy mouth and prevent thrush, practice good oral hygiene by brushing your teeth twice a day. Replace your toothbrush regularly—and definitely get a new one if you develop oral thrush. If you have a baby, regularly clean their toys, bottles, pacifiers, or anything else they often put in their mouth. If you have diabetes, see your dentist regularly. If you wear dentures, ensure that they fit correctly and clean them every night to prevent infection.

Sexual Health

If you suspect you have a yeast infection or have been diagnosed with one, abstain from sex until the infection is cured. Yeast infections can spread with sexual contact, including oral sex. This can give your partner an infection and could lead to you being reinfected after your infection clears up (Donders et al., 2010). In terms of lubrication, choose wisely. Some water-based lubes contain sugars, such as glycerin or sorbitol, to make them more slippery, which may essentially feed vaginal yeast. Invest in a good, nontoxic lube and stay away from petroleum jelly or anything in your kitchen cabinet as these oils can trap bacteria. (They also make latex condoms less effective.)

The Issue with Antibiotics

Antibiotics have been a huge triumph for worldwide public health. They treat many bacterial infections that were once severe and life-threatening illnesses. However, with the growing use of antibiotics worldwide, antibiotic resistance has become a major issue. When a person takes antibiotics, especially for too short a course, the weakest bacteria are killed, but the strongest, most resistant ones may survive and multiply. Overuse of antibiotics is one of the largest causes of drug-resistant bacteria. A 2016 study stated that over 30 percent of prescribed antibiotics are not needed (Fleming-Dutra et al., 2016). Antibiotics should be used only when a doctor prescribes them for a bacterial infection. Chronic use of antibiotics can lead to a disrupted microbiome as all of the native, good bacteria are killed along with the bacterial infection. When one type of organism is killed, the entire microbiome goes into flux, which can lead to a candida takeover and illness.

Contraception

Choosing the right form of contraception can be a long and arduous process, consisting of a lot of trial and error. You want something that you will use consistently, with minimal side effects, that’s effective—and doesn’t cause yeast infections. New research has suggested that certain contraceptives may encourage candida growth, increasing the risk for recurrent yeast infections.

A 2017 study found that women who started using hormonal IUDs or combined oral contraceptives increased their risk of yeast infections as well as bacterial vaginosis and trichomoniasis (Rezk, Sayyed, Masood, & Dawood, 2017). Another 2017 study found that women who used hormonal or nonhormonal (copper) IUDs had more vaginal candida compared to women who took progesterone-only oral contraceptive pills (Donders et al., 2017). A small 2016 study found that oral contraceptives containing estrogen were associated with increased candida counts in the mouth, suggesting that hormones effects on candida are not just localized to the vagina area (Aminzadeh, Sabeti Sanat, & Nik Akhtar, 2016). More studies are needed to piece out which contraceptives cause a potential issue for those who are candida-prone or whether it’s all contraceptives across the board.

Alternate Diagnoses and Treatment Options for Yeast Infections

Some functional and alternative health practitioners believe that candida goes beyond acute infections or rare invasive conditions. They believe that many individuals have chronic candida, perhaps without knowing it. The theory is that chronic yeast overgrowth leads to a vast array of symptoms and illnesses, including fatigue, leaky gut syndrome, and even depression. While modern Western medicine largely dismisses this theory, the idea has become popularized, specifically among people whose health conditions are not attributable to other diagnoses.

Chronic or Systemic Candida

Some practitioners believe it’s common for people to have candida overgrowth due to antibiotic or oral contraceptive use, poor diet, and environmental stressors. They believe that this can contribute to a wide variety of chronic illnesses that we see today, such as autoimmune conditions, digestive disorders, neurological conditions, and mood disorders. This is sometimes referred to as chronic candida, systemic candida, or simply candida. Symptoms can include just about anything: brain fog, mood swings, fatigue, eczema, sinus infections, dandruff, sugar cravings, and digestive issues, in addition to the more traditional topical rashes, oral thrush, or vaginal yeast infections (Boroch, 2015).

Functional health care practitioners may recommend a urine test or fecal test to determine levels of candida. Keep in mind, however, that candida is present in most people, and there may be wide variability in healthy levels of candida from person to person. In the Human Microbiome Project study, a healthy group of patients was found to have C. albicans species in 64 percent of their stool samples (Nash et al., 2017). A holistic practitioner may also recommend blood tests to check your levels of immune antibodies to candida. Self-spit tests have also grown in popularity, where you spit in a cup of water in the morning and wait fifteen minutes to see if the water turns cloudy, which would indicate candida. The self-spit test is not scientifically supported and is prone to error.

The Candida Cleanse Diet

Holistic doctors may recommend a candida cleanse diet, which involves removing some or all of the following from your diet: sugar, fermented foods, yeast, dairy, gluten, refined carbs, corn, alcohol, and caffeine. The theory is that these foods promote candida overgrowth, so removing them from the diet will reduce candida growth. While there have been no scientific studies to confirm this (see the lifestyle section), eating a healthier diet with less processed food and added sugars will almost certainly help you feel better, whether mentally or physically, and there seems to be little risk involved. For more on candida cleanse diets, see our article with functional medicine doctor Amy Myers, MD.

Practitioners may also recommend herbal antifungals for daily use or for use after a round of antibiotics. There are many dietary supplements on the market that claim to help with candida cleansing and support, but the majority of their ingredients do not have clinical studies to support their use.

New and Promising Research on Yeast Infections and Associated Health Issues

Scientists are beginning to better understand the mycobiome and how it may be related to gastrointestinal issues, mood disorders, and even Alzheimer’s disease.

The Mycobiome

The microbiome describes all the organisms throughout our whole body. The mycobiome is made up of the specific fungal communities in our bodies. Much of the existing research largely ignores our native fungal kingdom. The mycobiome is particularly interesting due to the distinct differences in the fungal makeup of different parts of our body, from our mouth to our gut to our skin, that researchers have only just begun to unearth. In a study of the makeup of healthy people’s gastrointestinal tracts, their mycobiomes contained a total of 184 fungal species, which were mostly candida species (Mukherjee et al., 2015).

Gastrointestinal Issues and Crohn’s

Various gastrointestinal issues beyond SIFO have been linked to candida overgrowth in the gut. Interactions between inflammation in the gut and candida may create a vicious cycle, leading to recurring intestinal issues.

In a 2017 study, researchers found that patients with Crohn’s disease, a gastrointestinal condition characterized by inflammation and scarring of the intestine, had higher levels of Candida tropicalis as well as the bacteria E. coli and Serratia marcescens compared to their non-Crohn’s family members. This particular yeast together with these bacteria can form a robust biofilm—essentially a mix of bacteria and fungi living in a thick, protective layer that protects them from antibiotics and immune cells. They also found that candida was able to create a thicker, more stubborn biofilm than other non-candida yeast species (Hoarau et al., 2016). The researchers, led by Mahmoud Ghannoum, PhD, are working on developing a novel probiotic (with the digestive enzyme amylase) that would break apart these biofilms and provide relief for patients with Crohn’s and other gastrointestinal issues (Hager et al., 2019).

More research is needed on how candida and gastrointestinal diseases are related—i.e., which one causes the other—and we hope to see more approaches to reduce and clear up biofilms.

Alzheimer’s Disease

Alzheimer’s is the most common cause of dementia, which involves memory loss and deterioration of other cognitive functions. But nobody really knows what causes Alzheimer’s—it’s probably some mix of genetic, lifestyle, and environmental factors that cause certain proteins (called amyloid and tau) to accumulate and form large deposits of plaque on the brain. But we still don’t know the basics, like does the amyloid itself cause damage? Or is it forming to play defense against invading bacteria that has been found in the brains of people with Alzheimer’s? New research has found that people with Alzheimer’s may also have fungus in their brains: A 2015 study by researchers in Spain compared the brains of Alzheimer’s patients to healthy controls. What they found was that every one of the Alzheimer’s patients had fungus in their brain sections and even in their blood, whereas the healthy controls did not. The researchers hypothesize that a fungal infection may trigger amyloid deposits to form in the brain, which leads to the development of Alzheimer’s (Pisa, Alonso, Rábano, Rodal, & Carrasco, 2015). For now, these are associations and hypotheses; much more research is needed to uncover how bacteria and fungi may be intricately related to Alzheimer’s.

Mood Disorders

You’ve probably heard of the gut-brain axis: A happy stomach makes a happy mind through an intricate connection between our microbiome and our mental health. Our gut creates much of our serotonin, and researchers have begun to figure out how your gut microbiome is related to depression and other mood disorders. Do our fungal communities—our mycobiome—affect our mental health? A 2016 study at Johns Hopkins found that men who tested positive for antibodies to Candida albicans in their blood (evidence of candida infection) had increased odds of a schizophrenia diagnosis (Severance et al., 2016). More research is needed to better understand this association.

Clinical Trials for Yeast Infections

Clinical trials are research studies intended to evaluate a medical, surgical, or behavioral intervention. They are done so that researchers can study a particular treatment that may not have a lot of data on its safety or effectiveness yet. If you’re considering signing up for a clinical trial, it’s important to note that if you’re placed in the placebo group, you won’t have access to the treatment being studied. It’s also good to understand the phase of the clinical trial: Phase 1 is the first time most drugs will be used in humans, so it’s about finding a safe dose. If the drug makes it through the initial trial, it can be used in a larger phase 2 trial to see whether it works well. Then it may be compared to a known effective treatment in a phase 3 trial. If the drug is approved by the FDA, it will go on to a phase 4 trial. Phase 3 and phase 4 trials are the most likely to involve the most effective and safest up-and-coming treatments. In general, clinical trials may yield valuable information; they may provide benefits for some subjects but have undesirable outcomes for others. Speak with your doctor about any clinical trial you are considering. To find studies that are currently recruiting for yeast infections, go to clinicaltrials.gov. We’ve also outlined some below.

MCT Oil for Infants

There is some preliminary evidence showing that medium chain triglycerides (MCTs), like the ones found in coconut oil, can protect against candida overgrowth. Joseph Bliss, MD, an associate professor of pediatrics at the Women and Infants Hospital of Rhode Island, is conducting a clinical trial to determine if MCT oil is beneficial for premature infants with detectable amounts of candida in their stool. Researchers will administer MCT oil to infants during their feedings for a minimum of two weeks or until they are discharged from the neonatal intensive care unit.

Better Diagnosis

There are many issues with the current methods for diagnosis and treatment of candida. It’s not only confusing, but it can also be risky for the patient if they’re not treated promptly and the candida spreads, causing other systematic issues. Robert Krause, MD, head of the section of infections and tropical medicine at the Medical University of Graz in Austria, is recruiting subjects for a clinical trial to determine if there’s a better way to diagnose invasive candidiasis. That is, are there biological markers that can help differentiate between normal colonization versus candida infection? As a secondary objective, they also hope to identify factors that increase people’s risk for invasive candidiasis, such as certain underlying diseases.

Immune Deficiency

Sergio Rosenzweig, MD, a pediatrician and clinical immunologist at the National Institutes of Health, is studying people with compromised immune systems to see what makes them so much more susceptible to fungal infections. Patients will be asked to provide their medical history, give blood and tissue samples, and undergo genetic testing so that researchers have a complete biological profile. This study will help uncover key factors related to candida and other fungal infections so they can be better understood and prevented in the future.

Related Reading on goop

1. • Leah Millheiser, MD, on how to avoid yeast infections and take care of your vagina

2. • Biologic dentist Gerry Curatola on how to take care of your oral microbiome

3. • Mycobiome researcher Mahmoud Ghannoum, PhD, explains how fungi impacts your body

4. • Functional medicine doctor Amy Myers, MD, walks us through her guide to probiotics