“This is the first time that dietary supplementation with soluble plantain has been shown to block bacterial invasion in an animal model,” note the authors based, in the main, at the University of Liverpool, the University of East Anglia and the University of Edinburgh.
In England and Wales, 9,685 human cases of Salmonella infection were confirmed in 2010, the most commonly isolated serovars were Salmonella enterica Enteritidis and Salmonella enterica Typhimurium 4/74.
Poultry-related products are one of the major sources of Salmonella infection for humans. Salmonella also causes considerable worldwide economic loss through chicken mortality, primarily caused by the avian-adapted serovars S. Gallinarum and S. Pullorum.
Writing in the journal, PLoS ONE, the scientists said while vaccination has been successfully used to reduce Salmonella in laying hens, the cost and practicalities make vaccines unsuitable for use in broilers.
The use of therapeutic antimicrobials against Salmonella is increasingly limited in poultry production due to problems with the emergence of resistant epidemic isolates, said the team.
And the authors note that since there are no vaccines to prevent salmonellosis or indeed other food-borne bacteria in humans, there is a clear need for an alternative preventative approach.
Soluble fibres from plantain banana plants - non-starch polysaccharides (NSP) - have been shown in vitro and ex vivo to prevent various enteric pathogens from adhering to or translocating across the human intestinal epithelium, said the authors.
To demonstrate that dietary plantain fibre prevents invasion of the chicken intestinal mucosa by Salmonella, the authors performed in vivo experiments with chicks fed from hatch on a pellet diet containing soluble plantain NSP (0 to 200 mg per day) and orally infected with S.Typhimurium at 8 days of age.
Bacteria were enumerated from liver, spleen and caecal contents.
In vitro studies were performed, said the researchers, using chicken caecal crypts and porcine intestinal epithelial cells infected with Salmonella enterica serovars following pre-treatment separately with soluble plantain NSP and acidic or neutral polysaccharide fractions of plantain NSP.
In chicks ingesting a custom-made commercial pellet diet supplemented with soluble plantain NSP there was significant reduction observed in the translocation of S. Typhimurium 4/74 across the chick gut, revealed the authors.
The most profound effect observed, with all three doses of ingested soluble plantain NSP (12.5, 50 and 200 mg per day), was a significant reduction in Salmonellae found in the splenic tissue compared to those birds on a non-supplemented NSP control diet, said the researchers.
Source: PLoS ONE
Published online: 3 February 2014; 9(2): e87658.
“Dietary Supplementation with Soluble Plantain Non-Starch Polysaccharides Inhibits Intestinal Invasion of Salmonella Typhimurium in the Chicken”
Authors: B.N. Parsons, P. Wigley, H.L. Simpson, J.M. Williams, S. Humphrey, A.M. Salisbury, A.J. Watson, S.C Fry, D. O'Brien, C.L. Roberts, N. O'Kennedy, A.V. Keita, J.D. Söderholm, J.M Rhodes, B.J Campbell