Okra polysaccharides inhibit adhesion of Campylobacter jejuni to mucosa isolated from poultry in vitro but not in vivo

In a previous study, high-molecular glycosylated compounds (polysaccharides and glycoproteins) from the immature fruits of the okra plant, Abelmoschus esculentus (L.) MOENCH, were shown to have a strong in vitro antiadhesive activity against Helicobacter pylori, leading to an inhibition of the binding to mucosal epithelia from human stomach in situ. For a further evaluation of okra compounds, aqueous extracts and polysaccharides were investigated concerning antiadhesive effects against the adhesion of Campylobacter jejuni on intestinal epithelia from chicken. In an in vitro adhesion model with fluorescent-labelled C. jejuni, the bacterial adhesion was shown to occur predominantly on jejunum and colon tissue, but only to a low extend on stomach, ileum and caecum tissue. Under these in vitro conditions, isolated okra polysaccharides strongly inhibited the microbial adhesion to colonic tissue. Within a controlled in vivo infection study over 42 days with chicken broilers infected by C. jejuni and fed with okra aqueous extract (50 and 100 g/kg) no significant reduction in Campylobacter excretion was observed, indicating that intestinal decontamination is not possible by the oral application of these compounds.