[Candida in the ecological system of the orointestinal tract]

Abstract

Within the microbial ecosystem of the orointestinal tract Candida spp. are common but not always detectable organisms. Therefore they belong to the transient flora. Candida spp. are found at various sites in healthy subjects in quantities between 10(2)-10(4)/ml or g. In different diseases an increased growth of Candida can occur depending on the presence of typical risk factors. In any case the yeasts only account for a minimal part of the bacterial flora. In this regard the contribution to the formation of metabolic products-in particular carbon dioxide, hydrogen and alcohols-is very small. Growth and development of Candida are dependent on nutrient and oxygen supply. In the colon under anaerobic conditions the flora competes for limited nutrients and fermentation is the dominant metabolic pathway in Candida. There is only minimal growth. Under aerobic conditions as can be demonstrated in experimental settings a marked growth with the formation of mycelium takes place. The generation time in vivo is much longer than under laboratory conditions and takes several hours. The detection of Candida in stool specimens can be interpreted in the first line only as a colonization. This is not equivalent with an infection, which, unfortunately, often is wrongly suggested in positive stool specimens.