Candida is a fungal genus of increasing medical concern. While important for normal health, imbalances in Candida can lead to disease, and systemic infections can be fatal. In this blog we give a complete overview of Candida; what it is, how it interacts with our bodies, and how we can diagnose and treat the conditions it causes.
Candida species and their role in human health.
Candida is a genus of yeast (a single-celled fungus) that is important for normal human health but can also be invasive and pathological. The first record of Candida comes from Ancient Greece in 400 BC where Hippocrates identified an oral infection and named it “thrush,” what modern doctors would call oral candidiasis. Since the time of Hippocrates, at least two hundred other Candida species have been identified, and around thirty of them are believed to be disease-causing.
In humans, Candida lives on the skin, and in the mouth, throat, gut, and vagina, playing beneficial roles in their local environment. Though each of us has a distinct gut microbiome, the most prevalent Candida species in the gut is usually C. albicans. Other clinically important Candida species include; C. glabrata, C. auris, C. tropicalis, C. parapsilosis, and C. krusei. These Candida species differ both in their infectivity and geographical distribution.
Differentiating between healthy candida populations and overgrowth.
Candida growing on and in our bodies are naturally suppressed by other microbes like bacteria, and by our immune system. However, when the microbiome is disrupted and/or the immune system is weakened, opportunistic overgrowth of Candida can occur.
What does overgrowth mean, and how do we distinguish it from normal growth? Overgrowth means increased Candida numbers have upset the normal microbiological balance and are present in sufficient amounts to cause disease.
The role of candida in the gut microbiome.
Revolutions in DNA sequencing technology have allowed us to take a snapshot of the microbes living in our digestive tract. For many years scientists wondered what Candida was doing in our gut. Was it a harmless commensal, or something less benign? Recent research has begun to untangle the complex role of candida in the gut microbiome.
- albicans may contribute to human health by priming the immune system against yeast infection and suppressing the growth of potentially harmful bacteria. Candida may produce metabolites for other microbes while acting as a scavenger for other by-products, thus aiding the gut ecosystem.
- C. albicans is thought to be highly adaptive to nutrient sources, enabling it to thrive in environments like the gut where the quantity and type of nutrients are in constant flux. However, this trait may also contribute to the pathological opportunism of albicans.
Types of Candidiasis conditions.
- Vulvovaginal Candidiasis – Very common infection of the lower female reproductive tract, most commonly caused by albicans. Symptoms include vaginal itching, pain, and vaginal discharge containing yeast, immune cells, vaginal fluid, and epithelial cells.
- Oral Candidiasis – Infection of the tongue and mucosa of the oral cavity, usually by albicans. Symptoms include the presence of creamy-white lesions, pain, redness, and loss of taste.
- Esophageal Candidiasis – Often follows oral candidiasis and is also predominantly attributable to albicans. Creamy-write lesions are present like in oral candidiasis, as well as difficulty swallowing and soreness along the esophagus.
- Cutaneous Candidiasis – Overgrowth of Candida on the skin resulting in an itchy, red rash. Commonly occurs in skin folds, between fingers and toes, and the genitals. Associated conditions include diaper rash and fungal nail infections.
- Invasive Candidiasis – Infection of deep-seated sterile organs such as the heart, liver, kidneys, and spleen, and also the bloodstream (a condition called candidaemia). Usually results from Candida overgrowth in the gut. Candidaemia can lead to severe sepsis which has a 70% mortality rate.
Symptoms of Candidiasis
Symptoms of Candidiasis vary depending on the location of the overgrowth and most are non-specific.
In addition to the symptoms mentioned above, Candidiasis can cause dizziness, loss of skin pigment, brain fog, sneezing, headaches, bloating, amnesia, itchiness, depression, constipation, diarrhea, cravings, weakness, fatigue, and allergy symptoms.
Who is most at risk from Candida?
Candidiasis affects all age groups but is more common in neonates and the elderly.
The risk factors for candidiasis are diverse, but broadly converge on two themes; suppression of immune function, and microbiome dysregulation.
Suppression of Immune Function – Immune cells help to keep Candida numbers at healthy levels and people with weakened immune systems are therefore particularly susceptible to candidiasis. These include the elderly, cancer patients, diabetics, HIV/AIDS patients, and COVID patients, among others. Patients undergoing surgery or dialysis, or using a catheter are high-risk, in addition to intravenous drug users.
Microbiome Dysregulation – It is widely accepted that Candida overgrowth in the gut and elsewhere results from a breakdown in the equilibrium between Candida and other microbes. High-sugar diets are increasingly prevalent and promote Candida growth leading to dysregulation. Prolonged broad-spectrum antibiotic use is a huge risk factor as it lowers the number of commensal bacteria shifting the balance towards Candida overgrowth. Impaired liver function reduces the abundance of digestive enzymes in the gut which normally suppress Candida overgrowth.
Methods of diagnosis and common treatment modalities.
- Candida is present in healthy individuals so the isolation of Candida is not in itself evidence of candidiasis.
- Many candidiasis symptoms are non-specific i.e., they may be caused by other conditions.
Thus, the diagnosis of Candidiasis relies on several factors. These include:
- Presence of Candidiasis risk factors
- Presentation of multiple symptoms
- Microbial Cultures
- Diagnostic Assays
Microbial cultures, i.e., taking a sample from the site of infection and culturing the resident microorganisms, remain the gold standard for diagnosing Candidiasis. However, a major limitation of this method is that it takes multiple days to get a result. Thus, non-culture diagnostics such as polymerase chain reaction, mass spectrometry, and fluorescence in-situ hybridization are becoming increasingly useful, especially in time-sensitive cases such as sepsis patients.
Treatments for Candidiasis
Antifungal agents are the first port of call for Candidiasis treatment and there are five classes:
- Polyenes – Work by binding to sterols, components of the fungal membrane.
- Pyrimidine Analogs – Work by disrupting fungal DNA biosynthesis.
- Azoles – Most commonly used, and work by disrupting membrane synthesis.
- Allylamines – Also disrupt membrane synthesis but through a different mechanism.
- Echinochanids – Work by disrupting fungal cell walls.
Increased incidence of Candidiasis and limited clinical anti-fungal repertoire has led to the emergence of multidrug-resistant strains, which are a major challenge for the field.
CanXida offers natural anti-Candida formulations with a wide band of action meaning no resistance will develop. In addition to novel antifungal compounds, prevention through exercise, sleep, stress management, and diet, remains central to controlling the global burden of Candidiasis.
In conclusion, infections caused by overgrowth of the Candida genus of fungi are on the rise globally. Weakened immune systems, long-term antibiotic use, and microbiome dysregulation are common risk factors for infection. Five classes of antifungals are currently used for treatment though multi-drug resistant strains have emerged. Natural formulations such as those offered by CanXida offer an alternative to Candidiasis treatment and symptom management.