Immune System And Yeast Infection

Overview

The immune system acts as our body's shield against infections, encompassing those caused by yeast. While the fungus Candida naturally exists in our body in minimal quantities, an imbalance between bacteria and yeast can cause it to multiply, resulting in a yeast infection. A robust immune system is pivotal in warding off such infections by maintaining this delicate balance. Nonetheless, specific elements can diminish our immune defenses, elevating the likelihood of yeast infections.

Understanding the immune system and yeast infection

About the immune system

The immune system is an intricate web of cells, tissues, and organs collaborating to shield the body from external threats like bacteria, viruses, and other harmful agents. 

When a pathogen enters the body, the immune system rapidly recognizes it as non-self and launches a series of responses to eliminate it.

These responses are specific, meaning that each pathogen is recognized by a unique pattern of molecular markers called antigens, and the immune system can respond specifically to each antigen. This specificity allows the immune system to respond rapidly and effectively to a wide range of pathogens without having to mount a new response each time.

Additionally, the immune response is designed to be protective, meaning that it works to neutralize or eliminate the pathogen and prevent it from causing further harm to the body. 

The immune system has several mechanisms in place to ensure self-tolerance. One of the main mechanisms is the process of negative selection, which occurs during the development of T and B cells in the thymus and bone marrow, respectively. 

During this process, cells that recognize self-antigens are deleted or become anergized, while those that do not are allowed to mature and enter the peripheral immune system.

Another mechanism of self-tolerance is the regulation of immune cells by regulatory T cells, which play a crucial role in preventing autoimmunity. These cells produce cytokines that dampen immune responses and promote tolerance to self-antigens.

Finally, the immune system also employs peripheral tolerance mechanisms, such as clonal deletion, anergy, and suppression, to prevent the activation of autoreactive immune cells.

In summary, self-tolerance is a fundamental aspect of the immune system that ensures that it does not attack the body's own tissues, preventing autoimmunity.

About yeast infection

Yeast infection, also known as candidiasis,  is a common fungal infection caused by species of Candida, most commonly Candida albicans. However, recent advances in molecular techniques have led to the recognition of additional species of Candida that can also cause infections.

Although Candida albicans is the primary culprit behind candidiasis, other strains like Candida glabrata, Candida tropicalis, and Candida parapsilosis are also emerging as notable contributors.

Candida can cause a range of infections, ranging from superficial skin and mucosal infections to invasive infections, such as candidemia and deep-seated infections. 

It is important to note that the appropriate treatment of candidiasis depends on the severity and type of infection, as well as the individual's overall health and medical history. As such, proper diagnosis and treatment by a healthcare provider is essential to ensure the best outcome.

The link between the immune system and yeast infection

Candidiasis arises when the yeast Candida albicans, typically harmless, proliferates excessively and turns harmful under specific conducive conditions. Such conditions include:

1. Antibiotic usage is a major factor that can contribute to the development of candidiasis. Antibiotics can disrupt the normal balance of bacteria in the body, leading to an overgrowth of Candida
2. Immature antimicrobial host defenses: Candidiasis is  more prevalent in older adults and infants, and it can occur in both males and females. The use of inhaled steroids in children and pregnancy in women can also increase the risk of developing candidiasis
3. Acquired suppression of immune defense mechanisms: Certain medical conditions, such as AIDS and chemotherapy or radiation therapy, can suppress the immune system, increasing the risk of oral thrush
4. Changes in environmental conditions of the oral cavity: Certain medications, such as antibiotics, can disrupt the normal balance of bacteria in the oral cavity, creating an environment conducive to the growth of Candida. The use of dentures can also increase the risk of oral thrush, as they can create an environment that is moist and warm, ideal for the growth of Candida

The use of oral contraceptives, tuberculosis, COVID-19, myxedema, hypoparathyroidism, Addison's disease, nutritional deficiency (vitamin A, B6, Iron), smoking, poorly maintained dentures, IV tubes, catheters, heart valves, pregnancy, can also increase the risk of candidiasis.

Invasive candidiasis is often caused by the translocation of the patient's own fungal flora, which can occur due to cytotoxic chemotherapy, dysbiosis and the use of intravenous catheters. The risk of invasive candidiasis increases with the presence of multiple risk factors, such as prolonged hospital stay, immune suppression, use of broad-spectrum antibiotics and other medical conditions that can disrupt the normal balance of bacteria in the body.

Summary

In a healthy individual, the immune system helps to maintain a balance of microorganisms in the body, including Candida, and prevents overgrowth of the yeast. However, when the immune system is compromised or weakened, Candida can overgrow and cause infections in case of: 

1. Chronic illness: Chronic illnesses such as diabetes, HIV/AIDS and cancer can weaken the immune system, making it more susceptible to candidal infections
2. Use of immunosuppressive drugs: Drugs that suppress the immune system, such as corticosteroids and chemotherapy drugs, can increase the risk of candidiasis
3. Antibiotic use: Antibiotics can disrupt the normal balance of bacteria in the body, leading to an overgrowth of Candida
4. Pregnancy: Hormonal changes during pregnancy can increase the risk of candidiasis
5. Nutritional deficiencies: Nutritional deficiencies, especially of iron, vitamins B6 and A, can weaken the immune system and increase the risk of candidiasis

In order to prevent yeast infections, it is important to maintain a healthy immune system by eating a balanced diet, getting regular exercise, avoiding excessive use of antibiotics and managing any underlying health conditions.