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Candida Albicans 

Karuna Professional Information Series #9104-9105

INTRODUCTION

Candida albicans is a yeast normally cohabiting with the normal microflora of the gastrointestinal tract and mucous membranes. The organism may become pathogenic when the system's ability to contain this commensal proves ineffective and proliferation of the yeast results in overgrowth. The current increase in the incidence of this condition appears to parallel the widespread use of broad-spectrum antibiotics, both as therapeutic agents and in the food supply.1 There are many factors which contribute singly or jointly to the overgrowth of Candida. Antibiotics, corticosteroids, pregnancy, oral contraceptives, diabetes mellitus, and immunosuppression are common predisposing factors.2 Physical manifestations of Candida overgrowth (Candidiasis) range from simple mucocutaneous lesions to polysysternic effects caused by absorption of toxins into the blood stream. In severely immunocompromised patients, actual colonization may occur in various organ systems resulting in impaired function.

HOST DEFENSES

Intact skin and mucous membranes create a physical barrier which comprises the first line of defense against Candida organisms. In addition, lysozyme in saliva, the immune globulin IgA from mucous membranes and fatty acids present in the gastrointestinal tract exert protective antimicrobial effects. The inflammatory response compromises the second line of defense. However, the Candida organism has the ability to exist as an intracellular pathogen and can utilize the phagocyte as a means of transport.3 The cellular and humoral responses of the lymphatic system comprise the next line of defense. In addition, the normal microflora of the intestinal tract act to inhibit the Candida organism both competitively and by producing nutrients, including vitamin K and certain B vitamins to strengthen the host. These aerobic bacteria include Lactobacillus, E. Coli, and Streptococci.4 Antibiotics which inhibit these friendly bacteria and corticosteroids which suppress the immunological response to the invader contribute greatly to the proliferation of Candida. Following the administration of antibiotics, the number of Candida organisms is often found to be greatly increased.5

FACTORS IN CANDIDA OVERGROWTH

C. albicans is a dimorphic organism which has the ability to change its physiology from a yeast to a mycelial fungal form. In the yeast state they are oval, single celled, sugar fermenting organisms. When conditions for Candida are favorable it may convert to the fungal form which will colonize, producing rhizoids (root-Eke structures) which are invasive and are capable of penetrating the mucosa, thereby impairing the boundary between the intestinal tract and the circulation.6 Candida can exist harn-Jessly contained as the yeast form in the gastrointestinal tract and vagina of most healthy individuals. In the presence of a properly functioning defense system which includes the elicitation of an inflammatory response to Candida, the organism generally remains as a yeast and is incapable of producing severe infection.7 The pathogenic hyphal form is favored in the absence of an inflammatory response.8

By eliminating competitive, protective bacteria, antibiotics facilitate Candida proliferation, since the yeast is not itself attacked by antibiotics. Furthermore, antibiotics have been postulated to inhibit phagocytosis, irritate the gut mucosa, and cause B-vitamin deficiencies by eradicating the bacteria involved in their production. 9 Steroids, including birth control pills, have a suppressive effect upon the immune system, appearing to cause delay in the activation of phagocytes. Evidence indicates that not only are patients on corticosteroids more susceptible to virulent strains of Candida-even normally non-pathogenic, less virulent strains may produce disease. 10

Elevations of estrogen and progesterone, as seen during pregnancy and with the use of oral contraceptives, are frequently associated with an increase in Candida-related infections. A progesterone-binding material has been isolated in the cytosol of the Candida organism and it is believed to be linked to the increased incidence of yeast infection during pregnancy, a time when progesterone levels are high.11 The link with estrogen is perhaps more obscure; however, it has been demonstrated that most cases of yeast-related vaginitis occur in women with estrogenized vaginal epithelium.12 Nutrient and fiber poor diets may contribute to Candida overgrowth because of alterations in the pH of the G.I. tract, which negatively affect friendly bacteria (which thrive in a characteristically narrow pH range), but do not inhibit Candida, which proliferates comfortably in a wider range of pH conditions.

CLINICAL MANIFESTATIONS

Pathogenic colonization with Candida albicans may manifest in a broad range of symptoms. It may be limited to the mucosal surfaces, resulting in oral thrush or yeast vaginitis. Colonization of the G.I. tract can produce nausea, constipation, diarrhea, flatulence, and abdominal burning or cramping.13) Penetration of the gastrointestinal mucosa by the invasive mycelia of the fungal form of C. albicans permits introduction into the blood stream of many substances which may be antigenic. Incompletely digested dietary proteins which enter circulation as a result of this leaky gut can exert a powerful antigenic impact on the immune system, resulting in a wide variety of food and environmental allergies. It has been postulated that toxins (such as acetaldehyde) elaborated by the fungus as metabolic byproducts of its life cycle may also enter the blood stream and account, in part, for the myriad of symptoms accompanying C. albicans overgrowth. Patients commonly complain of- weakness, fatigue, poor memory, poor concentration, joint pain, irritability, depression, mood swings, blurred vision, dizziness, headaches, and hypersensitivity to environmental pollutants, damp days and foods containing yeast, molds or sugars.14

The stage of acute infection of Candidiasis occurs when the organism itself actually invades the bloodstream entering the circulation. In these cases (generally severely immuno-compromised patients), the Candida can colonize in any organ, frequently on the heart valves, the brain, or in the kidneys. 15,16 The disease at this point becomes life-threatening and is becoming more commonplace in hospital settings due to the widespread use of antibiotics, chemotherapeutic agents and corticosteroids. It is frequently a component in the end stage sequelae of AIDS patients.

The organism itself may be a potent allergen. It may invade the bronchial tree, colonizing in the mucus secretions and inducing an asthmatic attack. Allergy to C. albicans is demonstrated by the raising of a wheal when skin is tested with Candida.. 17,18 Also frequently linked to Candida are other phenomena including arthritis19, psoriasis, PMS, and chronic urticaria. 20

DIAGNOSIS

The diagnosis of chronic Candidiasis is based upon etiological history, symptornatology and laboratory testing. Due to the presence of non-pathologic forms of the yeast in healthy individuals, it has been historically difficult to diagnose. Blood cultures were found negative in 56% of autopsy-proven cases of severe disseminated Candidiasis, according to a recent study in Reviews of Infectious Diseases.21 Only active infections are detected with blood cultures, since the organism itself needs to be present in the bloodstream to result in a positive culture.

At the present time, efforts are being made to perfect the detection of fungal antigens and metabolites in various bodily fluids. The EIA (Enzyme immunoassay) is one such test. The metabolic enzymes of the Candida organism are generally not found outside the cytoplasmic membrane. Due to their concealed position within the yeast cell, most people do not have antibodies against them unless they are heavily colonized by the organism.

Another approach recently employed is the detection of Candida-specific immune complexes and circulating free antigen which indicate the presence of a Candida overload with active replication of the yeast. The presence of free circulating antigen is unusual and indicates either that antibody production has yet to commence or that there is more antigen than available antibody to completely bind all the antigen.

SPECIFIC ANTI-FUNGAL AGENTS

Fatty Acids As early as 1913, the anti-fungal effects of various fatty acids had been recognized. Short chain fatty acids appear to be produced naturally by healthy intestinal bacteria where they exert an inhibitory effect on growth of pathogenic organisms.22 Hoffman et a]., conducted an extensive study in 1939 in which the fungicidal and fungistatic properties of normal saturated fatty acids were evaluated. The fatty acids containing from 7 to 12 carbon atoms were the most effective at inhibiting mold growth at a neutral pH. These fatty acids occur naturally in the body in glycerides and essential oils.23 Neuhauser, in 1954, reported on the effects of three to eighteen carbon straight chain fatty acids. She found caprylic acid, an eight carbon acid, to have the greatest fungicidal activity against Candida.24 Caprylic acid is a natural component of food fats and human sweat. It has also been found to have no inhibitory action against the normal intestinal bacteria. No undesirable side effects have been reported.25

Sorbic acid in both its dissociated and undissociated forms was found by Eklund in 1982 to demonstrate antimicrobial action against various organisms, including Candida. It acts on the cellular membrane of the organism, blocking uptake of amino acids.26 Sorbic acid, obtained from the berries of the mountain Ash, is safely metabolized by the body.27

Propionic acid is a three carbon saturated fat with proven fungicidal properties. At a pH of 5 it was observed to inhibit C. albicans in concentrations of 0.03.28 It helps prevent conversion of Candida to its pathogenic form. The salts of propionic acid were found as effective as the acid form.29

VITAMIN SUPPORT

A biotin deficiency is necessary for the conversion of Candida from its non-pathogenic yeast form to its pathogenic hyphal form.

Beta carotene and Vitarnin A are essential for enhancement of the integrity of the intestinal mucosa, which, as mentioned earlier, is the body's first line of defense against Candida invasion.

Vitarnin E as an antioxidant is helpful in protecting fatty acids against free radical damage and may preserve their usefulness as anti-Candida agents.

Garlic

Throughout history, garlic, or Alliurn sativurn, has been used therapeutically for a wide variety of problems. One of the most important and thoroughly researched effects is as an antimicrobial agent. Garlic has been found to have potent antifungal qualities, being particularly active against Candida albicans. In fact, several studies have found it to be more potent than several of the traditional allopathic anti-fungal agents, including Nystatin and Gentian violet.30

CLINICAL MANAGEMENT OF CANDIDA ALBICANS

The yeast form of Candida is more responsive to treatment than the more intractable fungal form. The program for both is many-faceted and may take from a month to a year to manifest results.

A good diet and nutritional supplements are important in nourishing the host, in preventing the conversion of Candida to its fungal form, and in maintaining proper pH. Food elimination or rotation diet will help to minimize food antigens and foods (such as refined carbohydrates) which appear to nourish Candida. A diet high in fiber will hasten the elimination of metabolic byproducts of the organism as well as the dead organisms themselves.

BACTERIAL ADJUNCTS

Candida overgrowth is facilitated when the normal balance of healthy organisms in the gastrointestinal tract becomes disturbed. Reinoculation of the bowel with preferred symbiotic acid-producing bacteria such as Lactobacillus, bifidus, and Streptococcus faeceiurn helps to contain Candida by establishing proper pH, direct competition and enhanced nutrient production of friendly bacteria. Lactobacillus acidophilus is one of the predominant lactobacilli present in the intestines of healthy individuals and research has shown it to be inhibitory against C. albicans.31 It inhibits the growth of other organisms through alterations of pH and oxygen tensions, by competition for nutrients, by mechanically blocking attachment sites for pathogenic organisms and, finally, by actually producing antimicrobial substances.32

 

Bibliography available upon request

CAPRIGAR

MICROSOFT WORD

F: BARBARA, TECHSHT

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