A polyamine is an organic compound having more than two amino groups. Alkyl polyamines occur naturally but are also synthetic. Alkylpolyamines are colorless, hygroscopic, and water soluble. Near neutral pH, they exist as the ammonium derivatives. Most aromatic polyamines are crystalline solids at room temperature. Polyamines are polycations that interact with negatively charged molecules such as DNA, RNA and proteins. They play multiple roles in cell growth, survival and proliferation. Changes in polyamine levels have been associated with aging and diseases. Sources of polyamines may be endogenous or exogenous.The (trophic) effects of S. boulardii are at least in part mediated by polyamines. Polyamine concentrations in the mucosa and the endoluminal fluid have been shown to increase after yeast treatment, and disaccharidase activities and Na+-dependent glucose uptake in ileal brush border vesicles.