Turku sugar studies III. An intermediate report on the effect of sucrose, fructose and xylitol diets on the numbers of salivary lactobacilli, Candida and streptococci

Publisher Website
Google Scholar
Abstract
The possible alteration of the ecological balance of the microbial flora when replacing dietary sucrose with xylitol or fructose was analyzed. A serial dilution of saliva samples was made and plated on Rogosa SL agar and on Sabouraud Dextrose agar with antibiotics. After aerobic incubation at +37°C the colonies of lactobacilli, streptococci and yeasts were identified and counted. No significant differences were observed among the samples which were taken on two consecutive days at the baseline examination before the onset of the experiment. On Rogosa agar a trend to decrease was observed in the number of lactobacilli after one month's diet in all the sugar groups. After 8 months' diet, the growth on Rogosa agar was increased in the fructose and sucrose groups and remained unchanged in the xylitol group. The number of Candida colonies on Sabouraud agar was reduced by about 70%, as well as the percentage of persons with salivary Candida growth by about 60%, in the xylitol group, whereas a slight increase was observed in the fructose and sucrose groups. The difference between the groups was significant and was thought to be a direct effect of xylitol on the ecology of the oral cavity.