PWE-180 The Acidic Polysaccharide Component of Soluble Plantain Fibre Inhibits the Adhesion of Diarrhoea-Associated Pathogens Salmonella, Clostridium Difficile and Enterotoxigenic Escherichia Coli to Intestinal Epithelial Cells
Authors: H L Simpson, B N Parsons, J M Rhodes, B J Campbell
Journal: Gut (2013)

<h3>Introduction</h3> Pathogen-related diarrhoea is a major problem worldwide, causing significant morbidity and mortality each year. Our recent studies have shown that soluble dietary fibre (non-starch polysaccharides, NSP), particularly those from plantain bananas (<i>Musa</i> spp.), can inhibit the adherence of diarrhoeal pathogens such as <i>Salmonella</i>, <i>Clostridium difficile</i> and enterotoxigenic <i>Escherichia coli</i> (ETEC) to the intestinal epithelium (J. Nutri. Biochem. 24:97–103). Our aim in this study was to elucidate specific polysaccharide components present in soluble plantain fibre that confer bioactivity to block diarrhoeal pathogen interaction with the gut epithelium. <h3>Methods</h3> Plantain NSP was separated into neutral and acidic component polysaccharides using Q-Sepharose strong anion-exchange chromatography. Unbound neutral oligosaccharides were collected from the flow-through and Q-Sepharose bound acidic polysaccharide fractions were eluted stepwise with 0.25, 0.5 and 1M NaCl. All fractions were desalted on PD MidiTrap G10 mini-columns. Purified fractions were assessed for inhibitory action on <i>C. difficile</i> 027A, ETEC C410 and <i>S.</i> Typhimurium adherence to human and porcine epithelial cell monolayers in the presence of plantain NSP and its fractions (30 min pre-treatment prior to infection), at MOI 100 for 90 min (for ETEC and<i> Salmonella)</i> or 120 min (for <i>C. difficile</i>). Adherent colony forming units (CFU) were enumerated by overnight growth on LB-agar. <h3>Results</h3> As observed for plantain NSP, at 5mg/mL, a Q-Sepharose-purified acidic polysaccharide fraction of soluble plantain NSP also significantly blocked adhesion to human Caco2 colonocytes of gut pathogens <i>C. difficile</i>, by 52.3±7.3%; ETEC, by 74.8±15.1; and<i> S</i>. Typhimurium, by 92.1±2.91% (all P &lt; 0.001 Kruskal-Wallis; N = 2 experiments, each with n = 3 replicates). Conversely, pre-treatment of Caco2 cells with the neutral polysaccharide fraction of plantain NSP showed little ability to reduce adhesion of <i>C. difficile</i> (10.2% inhibition) and a reduced ability to inhibit interaction of <i>Salmonella</i> or ETEC (46.6% and 39.1% inhibition respectively). Similalrly, acidic fractions of plantain NSP at 5mg/mL also blocked adhesion of S. Typhimurium to porcine enterocytic cell-line B10XI compared to untreated control (N = 4, n = 4; <i>P</i> &lt; 0.01 Kruskal-Wallis). <h3>Conclusion</h3> Our findings indicate that the inhibitory activity of plantain NSP against diarrhoeal pathogen interaction with the host intestinal epithelium lies in its acidic (pectic) polysaccharide component. Disruption of bacterial-epithelial adherence to the intestinal mucosa by soluble plant fibres, acting as ‘contrabiotics’, may prove to be of therapeutic benefit. <h3>Disclosure of Interest</h3> H. Simpson: None Declared, B. Parsons: None Declared, J. Rhodes Grant/Research Support from: Provexis plc (UK), Consultant for: A member of advisory boards for Atlantic, Proctor and Gamble, Falk, Conflict with: Lecture fees received from Abbott, Falk, Ferring, Glaxo Smith Kline, Proctor and Gamble, Schering Plough, Shire, Wyeth. With the University of Liverpool and Provexis UK, holds a patent for use of soluble plantain fibre as maintenance therapy for Crohn’s disease plus a patent pending for its use in antibiotic associated diarrhoea, B. Campbell Grant/Research Support from: Provexis plc. and Shire, Consultant for: Amgen Inc.