Regulation of Candida albicans populations in the gastrointestinal tract: mechanisms and significance in GI and systemic candidiasis.

Abstract

Colonization of the gastrointestinal (GI) tract by Candida species, and C. albicans in particular, may play an important role in human health and disease, as the GI tract has been implicated as an important source of infection in cases of recurrent vaginitis (104) and systemic candidiasis (94,112,149–151,164). The overgrowth of C. albicans in the intestinal tract and its subsequent passage through the gut mucosa into the host bloodstream, for instance, is believed to be the proximate mechanism leading to systemic candidiasis (151), particularly in patients with acute leukemia (103,112,129). Similarly, colonization of the GI tract by C. albicans and other Candida spp. may lead to involvement in a number of other disease syndromes that include esophageal, gastric and intestinal thrush, gastric and intestinal ulceration, GI bleeding, diarrhea, peritonitis, perianal itch, napkin dermatitis, chronic “irritable bowel” syndrome, and auto-brewery syndrome (12,59,60,80,81,94,102,106,112,117,118,130,131,149–151,156, 164,165,171). The importance of GI colonization by C. albicans therefore should not be underestimated, especially in view of the suggestion that “the most important source of Candida species in human disease is endogenous” (118). On the other hand, GI colonization by C. albicans may also have important beneficial effects on the host in that it apparently results in stimulation of the immune system, leading to a protective response to systemic Candida infection in the noncompromised host (31,32).