Kefiran, an exopolysaccharide isolated from kefir d'acqua grains, has anti-inflammatory and antimicrobial activities, however, a mechanism of action directly associated with biomembranes is not yet understood. The influence of kefiran on a L-alpha-Phosphatidylcholine/cholesterol supported bilayer lipid membrane using a Pt electrode was studied by voltammetry and electrochemical impedance spectroscopy. The interaction of the oligosaccharide with s-BLMs promoted the access of Fe(CN)(6)(3-/4-) probe ions to the electrode surface. Kefiran was found to induce molecular pores at the s-BLM surface within 5 min at 11.4 mu mol/L. The suggested mechanism seems to involve hydrogen bonding between the carbohydrate and the phosphate head group of the phospholipid with a carpet-like model of interaction. The overall results can be contributed to direct molecular interactions between the prebiotic oligosaccharides and the cell surfaces, which can be related to the biological activity of kefiran in several experimental models. (C) 2011 Elsevier B.V. All rights reserved.