Candida: uncovering the facts, debunking the myths

Since my work involves frequent contact with people experiencing various health issues, I often come across the belief that many of these problems are caused by Candida spreading throughout the body. The presence of this yeast is supposedly confirmed by a saliva test, which I will describe in detail later. Because I tend to be skeptical when so many different problems are attributed to a single cause, I decided to look deeper into the topic and found that many claims about the problems Candida is said to cause cannot currently be supported by solid scientific evidence.

Candida is a genus of fungi from the yeast family, comprising around 200 different species, eight of which most commonly cause infections in humans. By far the best-known species in this genus is Candida albicans. In this article, I will refer to it simply by its Slovenianized name, as it is most widely known among people: Candida.

“The concept of chronic systemic candidiasis is based on assumptions rather than evidence.”

Candida can indeed overgrow in the body and cause problems

Although Candida is part of the normal intestinal, and often also mucosal and skin flora, its excessive growth under normal conditions is limited by the population of other microorganisms living there, primarily bacteria. In the intestinal flora, Candida competes and coexists with more than 300 types of bacteria. Its overgrowth can be triggered, for example, by antibiotic therapy, since antibiotics destroy bacteria but, of course, have no effect on fungi. A mouse study (2013) found that the intestine normally contains three times more bacteria than fungi, but that during antibiotic therapy, Candida can multiply up to 40-fold, after which the ratio spontaneously returns to normal within eight weeks.

Vaginal and penile candidiasis

Despite its high prevalence, vaginal Candida infections usually do not cause more serious problems than unpleasant itching. During sexual intercourse, it is often transmitted to the partner and can cause a fungal infection of the penis (penile candidiasis).

Oral candidiasis

Candida is present in the oral cavity in up to 75% of individuals and does not cause problems in healthy people. In individuals with a weakened or not yet fully developed immune system, it can cause a fungal infection of the oral mucosa, known as oral candidiasis (it occurs in 6% of newborns under one month of age, 20% of patients with HIV, and the same percentage of patients undergoing chemotherapy). Risk factors include:

• HIV infection
• chemotherapy
• Wearing dentures
• Advanced age

Invasive candidiasis

If Candida enters the bloodstream, it is called invasive candidiasis or candidal sepsis. This is a very rare but extremely serious condition, with a mortality rate of over 60%. It occurs in up to 14 people per 100,000 inhabitants, typically in severely ill individuals with a profoundly weakened immune system. Two-thirds of such infections occur in hospitalized patients. In Europe, Candida ranks between sixth and tenth among the causes of sepsis in hospitalized patients, while in the United States it ranks fourth.

There are also certain health conditions in which Candida may play a role. Some authors associate an imbalance in the natural intestinal flora with diseases such as Crohn’s disease or graft-versus-host disease. It should be noted, however, that these studies only demonstrate a correlation and not proof that Candida actually causes these diseases.

Some claims about Candida overgrowth simply don’t make sense

Systemic candidiasis or candida overgrowth

The first person to claim that Candida was responsible for a wide range of symptoms was William G. Crook, who published his theory in a book in 1986. He called the condition systemic candidiasis or Candida hypersensitivity and attributed to it the following symptoms:

• Fainting,
• weight gain,
• constipation,
• dizziness,
• muscle and joint pain,
• asthma,
• psoriasis,
• sexual dysfunction,
• bloating,
• irritability,
• diarrhea,
• mood swings,
• depression,
• anxiety,
• concentration problems,
• respiratory and ear problems,
• menstrual problems,
• Infertility,
• urinary tract infections,
• inflammation of the prostate, and
• general malaise.

The American Academy of Allergy, Asthma & Immunology has published a book strongly criticised and accused the author of:

• the concept of chronic systemic candidiasis defined in the book is based on assumptions rather than evidence.
• that the symptoms the author claims are caused by Candida could be found in practically anyone who doesn’t feel well and that these symptoms are very nonspecific.
• Because the author recommended the use of antifungal medications, the Academy warned that using such drugs could lead to the overgrowth of other microorganisms that normally compete with Candida in the natural flora, thereby causing an imbalance of the microbiome.

Crook responded to the accusations by saying that he did not provide evidence for his claims because he was a doctor, not a researcher.

"Being open-minded also means being cautious. To present evidence and claim that everything is clear where it is not is dangerous and unfair to the millions of people who are looking for answers to their problems."

Candida and nail fungus

Some claim that signs of Candida overgrowth in the body are nail and skin fungus as well as athlete’s foot. In reality, however, most fungal infections of the nails and skin are caused by dermatophytes, a completely different group of fungi than Candida. Nail infections caused by fungi of the Candida genus account for 29% of nail infections, most of which are due to other Candida species — specifically Candida parapsilosis (42%) and Candida guilliermondii (20%), while Candida albicans accounts for only 14%, meaning roughly 4% of all nail fungal infections.

• Repeatability and
• Specificity

While criteria such as accuracy, sensitivity, and detection limits can be quite flexible depending on the purpose of a given method, repeatability and specificity are of crucial importance. If a method does not meet these two criteria, it is considered invalid. Let’s see how the saliva test, which supposedly proves that Candida is attacking us, performs according to these criteria:

Repeatability

The repeatability of a method refers to its ability to produce consistently similar results on the same sample under the same conditions. In biomedical laboratories, the repeatability of each method is checked daily using control samples with a precisely defined and pre-known concentration of the measured substance. Take a thermometer as an example. When you have a fever, you expect the thermometer to show your actual body temperature. If you take a series of measurements a few minutes apart and the thermometer shows 41°C, then 35°C, and then 38°C, such a measurement method is useless — and the thermometer belongs in the trash. Of course, minor deviations are always acceptable because measurement errors are inevitable. For instance, readings of 37.1°C, 37.0°C, and 37.2°C would be perfectly fine. Likewise, you wouldn’t be happy if your bathroom scale showed 50 kg in the morning, 80 kg at noon, and 100 kg in the evening — in that case, the scale would join the thermometer in the trash bin.

And what does this have to do with the saliva test that supposedly proves Candida has overrun our body, you might ask. The result of the saliva test is different every morning. One day, the saliva will appear cloudy and form threads, and the next day it will float compactly on the surface of the glass for half an hour. Does that mean Candida is present in our mouth today but will be gone tomorrow?

Specificity

Analytical specificity is the ability of a method to detect only the target substance being measured. In the case of the saliva test, that would be Candida alone. Proponents of this test claim that Candida is present in your morning saliva. This is very likely true, as Candida is found in the oral cavity of up to 75% of individuals, but in healthy people, it does not cause any problems. However, our mouths also contain many other things: more than 300 species of bacteria, saliva that may contain varying amounts of mucin polysaccharides, food residues between the teeth, and countless other factors that can affect the viscosity of your saliva. The claim that saliva forms threads and appears cloudy because it contains Candida is therefore just like the hunter’s tale who insisted he was attacked by a huge bear after hearing rustling in the bushes.

What I want to emphasize is that a lot is happening in the mouth, and these processes are not dependent on whether Candida is present or not. There is more mucin in the saliva if you have a cold or if you consume dairy and other foods that stimulate mucin production. The viscosity of saliva is also influenced by exposure to allergens, as well as by how much and when you last drank fluids.

The saliva test is therefore a completely nonspecific test of saliva viscosity.

Conclusion

Theories about widespread systemic candidiasis are currently not supported by any evidence. The natural flora plays an important role in our health — this is well known and agreed upon by all experts. There is still much to learn about the influence of the natural flora, including fungi, on our health. Many studies are being conducted in this field, and they may reveal things we do not yet know. However, being open-minded also means being cautious. Ignoring evidence and claiming that everything is clear when it is not is dangerous and unfair to the millions of people who are seeking answers to their problems.

So when you ask us whether Smrekovit capsules are suitable for Candida — the capsules are very effective for many digestive issues, regardless of their cause. Some people indeed attribute most of these problems to Candida overgrowth. Whether such reasoning is justified or merely an assumption without evidence is for you to decide based on this article.

Frequently asked questions and answers

The literature used for this article can be found at this page.