Limited effect of refined carbohydrate dietary supplementation on colonization of the gastrointestinal tract of healthy subjects by Candida albicans

Background: Infections due to Candida albicans occur readily in situations in which ample glucose is available. In mice, dietary refined carbohydrate supplementation leads to higher rates of Candida growth in the gastrointest inal tract and favors mucosal invasion. Objective: The modulating properties of dietary carbohydrate supplementatio n on colonization of the human gastrointestinal tract by C. albicans were e valuated. Design: A 2-step study was conducted in 28 healthy volunteers. First, we de termined the subjects' habitual uptake of refined carbohydrates and correla ted these data with the C. albicans blastoconidia concentration in the mout h washes and feces of subjects with no intervention. Second, we compared C. albicans counts in the specimens before, during, and after a high-sugar di et. Results: No correlation between C. albicans counts in the specimens and the habitual uptake of refined carbohydrates was observed. A high-sugar diet d id not increase the frequency of C. albicans-positive samples, the number o f subjects positive for C. albicans in the mouth washes, or the concentrati on of candidal blastoconidia in the samples of the 28 subjects. However, in selected subjects with elevated counts of oral C. albicans, we observed an increase in fecal C, albicans counts in response to the diet. Conclusions: The effect of adding a high amount of refined carbohydrates to the diet of healthy human subjects has a limited influence on Candida colo nization. Follow-up studies should define whether selected patient groups m ight benefit from dietary restriction of refined carbohydrates.