The potential role of soluble plantain fibre and its components in preventing colonisation and invasion of the intestinal mucosa by S.Typhimurium.

There is growing interest in the potential beneficial effects of the dietary intake of plant fibres and their interaction with the bacteria inside the intestine. This applies not only to man but also potentially to animals that enter the human food chain. The gastroenterology research group in Liverpool have identified a novel mechanism by which soluble plant fibres may be protective - acting by blocking recruitment of bacteria to the lining of the intestine. The group has tested a wide range of plant fibres and found that fibres from plantains (a form of banana that is usually eaten as a vegetable after cooking) are particularly potent at inhibiting bacterial recruitment and that this plantain fibre is active against a wide range of pathogens. The group already has a collaboration with a Biotech company Provexis plc (Provexis IBD Ltd), which until now has focussed on prevention of human disease. The current project is a new collaboration, together with the University of Liverpool Veterinary School, that is targetting Salmonellosis in poultry. This is a huge public health problem which also has major financial implications for the poultry industry. There is widespread acknowledgment that antibiotic therapy of poultry is not a good solution and a simple dietary intervention such as addition of a specific inhibitory plant fibre to poultry feed would be extremely valuable if it were shown to reduce Salmonellosis. This project will analyse the different fibre structures within plantain, identify those fibre types that seem particularly inhibitory against Salmonella in the laboratory and then test these fractions in chickens that are also challenged with Salmonella infection in a controlled research environment.

There is growing interest in the potential beneficial effects of plant fibres on intestinal health. Most of the work to date has focussed on prebiotic effects, i.e. increased growth of probiotic bacteria. Prior work by the applicants suggests an alternative protective mechanism - inhibition of bacterial adherence to the epithelium by soluble plant fibres, probably acting via inhibition of lectin-carbohydrate interactions. The applicants have tested a range of soluble plant fibres in vitro for their ability to block pathogen-epithelial interaction and shown that soluble plantain (green banana) fibre is particularly inhibitory. In vitro modelling of the human intestinal microbiota has shown that inhibitory fibre concentrations could be readily achievable even in the distal colon. Human clinical trials in inflammatory bowel disease are now underway in collaboration with a Biotech partner Provexis plc (Provexis IBD Ltd). Provexis have established a reliable source of the fibre and a reproducible manufacturing process that reaches the high standards required for a medicinal product. The principal scientist at Provexis plc, who is a partner in this application, has particular expertise in plant fibre chemistry. The proposed research is a new collaboration with the University of Liverpool Veterinary School to assess whether soluble plantain fibre could also be used to reduce colonisation of poultry by pathogens. The principal focus will be on prevention of Salmonellosis since this is a well tried model. The aim is to assess not only whether addition of soluble plantain fibre to poultry feed reduces Salmonella colonisation and invasion but also to determine which fibre fractions are most inhibitory and then to obtain preliminary characterisation of the composition and structure of the inhibitory fibres.