Batch culture techniques were used to study the effect of sorbitol and xylitol on the aggregation, adhesion and solubility of the polysaccharides produced by Streptococcus mutans in the presence of 3% sucrose. Both polyols increased the production of soluble polysaccharides: control < xylitol xylitol. Thus, in cell-cell and cell-glass interactions of S. mutans, the ratio of easily soluble to insoluble polysaccharides seems to play a more important role than the absolute amounts of soluble, insoluble or total polysaccharides per