PMO-030 Soluble plant fibres, particularly leek and plantain, inhibit adherence of diarrhoea-associated pathogens<i>C difficile</i>and enterotoxigenic<i>Escherichia coli</i>to intestinal epithelial cells
Authors: H L Simpson, C L Roberts, J M Rhodes, B J Campbell
Journal: Gut (2012)

<h3>Introduction</h3> It has long been thought that dietary fibre promotes intestinal health and we have previously shown that the soluble non-starch polysaccharide (NSP) from plantain bananas (<i>Musa</i> spp.) can inhibit the epithelial adhesion and microfold (M)-cell translocation of Crohn9s-associated <i>Escherichia coli</i> (<i>Gut</i> 2010;<b>59</b>:1331–9) and a range of diarrhoeal pathogens including <i>Salmonella</i> and <i>Shigella</i> (<i>Gut</i> 2011;60:A96). Here we examined NSP from representative examples of monocotyledon and dicotyledon plant fibres, for efficacy to inhibit epithelial interactions of <i>Clostridium difficile</i>, a major cause of antibiotic associated diarrhoea, and enterotoxigenic <i>E coli</i> (ETEC), the commonest cause of traveller9s diarrhoea. <h3>Methods</h3> Human intestinal epithelial cell-line Caco2-cl1 cell monolayers were pre-treated for 30 min with NSP preparations, including those from vegetable (broccoli, leek), fruit (plantain, apple) and cereal (oat) sources, followed by infection with <i>C. difficile</i> (for 2 h, at multiplicity of infection MOI of 100) or ETEC (4 h; MOI 100). In parallel experiments, adherence of bacteria to cell monolayers was examined following fixation, Giemsa stain and light microscopy. <h3>Results</h3> <i>C difficile</i> adhesion to Caco2-cl1 cells was significantly inhibited in the presence of broccoli, leek and plantain NSP. Leek NSP, at 5 mg/ml, had the most significant effect on inhibition of <i>C difficile</i> adhesion (54.9±9.7% reduction) compared to untreated controls (n=3−9, p&lt;0.001, ANOVA). Neither apple nor oat NSP had any significant ability to prevent <i>C difficile</i> adhesion to CaCo2-cl1 cells. ETEC adhesion to CaCo2-cl1 cells was also significantly inhibited in the presence of leek NSP (53.7±13.6%; p&lt;0.01) and plantain NSP (40.9±9.3%; p&lt;0.001) but no efficacy was observed for soluble broccoli, apple nor oat fibre. Blockade of adherence to Caco2-cl1 cells by NSP was also confirmed by Giemsa stain. <h3>Conclusion</h3> Leek, plantain and/or broccoli NSP show efficacy at blocking <i>C difficile</i> and ETEC adhesion in a dose dependent manner to the intestinal epithelium in vitro and at concentrations readily achievable in vivo. The close proximity of <i>C difficile</i> and ETEC to the host epithelium is almost certainly essential for the release of their respective toxins and the exertion of their pathogenic effect. Disruption of bacterial-epithelial adherence to the intestinal mucosa by soluble plant fibres may therefore be of therapeutic benefit. <h3>Competing interests</h3> H Simpson grant/research support from: industrial case studentship with support from Provexis plc, C Roberts conflict with: past employee of Provexis plc, J Rhodes consultant for: is a member of advisory boards for Atlantic, Procter and Gamble and Falk, speaker bureau with: Has received speaking honoraria from Abbott, Falk, Ferring, Glaxo Smith Kline, Procter and Gamble, Schering Plough, Shire and Wyeth, Conflict with: holds a patent with the University of Liverpool and Provexis UK for use of a soluble fibre preparation as maintenance therapy for Crohn9s disease plus a patent pending for its use in antibiotic-associated diarrhoea, B Campbell grant/research support from: grant support from Provexis plc and the Bo &amp; Vera Ax:son Johnson Foundation Ltd.