Tolerance to gastrointestinal conditions, adhesion to Caco-2 cell line and inmunomodulation properties of Pediococcus parvulus 2.6 strain producing 2-substituted (1-3)-B-D glucan

MARÍA LAURA WERNING,; PILAR FERNÁNDEZ DE PALENCIA; MARÍA TERESA DUEÑAS; ANA IRASTORZA; ANGEL CORBÍ; PALOMA LÓPEZ

Simposio; IX SYMPOSIUM ON LACTIC ACID BACTERIA: HEALTH, EVOLUTION AND SYSTEMS BIOLOGY; 2008

Abstract A variety of bacteria, animals and plants produce extracellular polysaccharides (EPS). Among these, the (1→3)-β-D-glucans can promote antitumor and antimicrobial activity. The immunomodulating properties of the (1→3, 1→2)-β-D-glucans have not been reported. The Pedioccocus parvulus 2.6 strain carries the pPD2 plasmid encoding a glucosyltransferase, which synthesizes this type of EPS. In this study, the probiotic potential of strain 2.6 and the isogenic 2.6NR (pPD2 cured) has been investigated. The viability of the strains was assessed after exposing them in vitro to gastrointestinal stress conditions. Furthermore, human intestinal epithelial-like Caco-2 cells were used to examine the adhesion of the bacteria and their ability to stimulate pro-inflammatory cytokine production in this cell line. Both strains exhibited a reduction of its survival after gastric treatment at pH 5.0 and further incubation with intestinal secretions, indicating that the ability to produce EPS (detected by electron microscopy) did not protect P. parvulus against gastrointestinal stress. By contrast, the adhesion of 2.6 to enterocytes was two-fold higher than that of 2.6NR strain. Moreover, the high adherence of the EPS producer (6%) to Caco-2 cells was partially abolished (decrease to 1.8%) after EPS removal by washing. The absence of induction of the pro-inflammatory cytokines IL-6 and IL-8 by human intestinal epithelial cells, indicated that P. parvulus 2.6, like other probiotic bacteria, attaches to the epithelial cells without triggering local inflammatory response.